ML13175A240
| ML13175A240 | |
| Person / Time | |
|---|---|
| Site: | South Texas  |
| Issue date: | 06/06/2013 |
| From: | Letellier B C, Sande T D, Zigler G L Enercon Services, South Texas, Los Alamos National Laboratory |
| To: | Office of Nuclear Reactor Regulation |
| References | |
| GSI-191, NOC-AE-13002986 STP-RIGSI191-V03, Rev 1 | |
| Download: ML13175A240 (161) | |
Text
NOC-AE-1 3002986 ENCLOSURE 4-3 Risk-Informed Closure of GSI-191 Volume 3 Engineering (CASA Grande) Analysis South Texas Project Risk-Informed GSI-191 Evaluation Volume 3 CASA Grande Analysis Document:
STP-RIGSI191-V03 Revision:
1 Date: June 6, 2013 Prepared by: Timothy D. Sande, Enercon Services, Inc.Bruce C. Letellier, Los Alamos National Laboratories Gilbert L. Zigler, Enercon Services, Inc.Reviewed by: Joseph E. Tezak, Enercon Services, Inc.W.E. Schulz, South Texas Project Ernest J. Kee, South Texas Project Zahra Mohaghegh, Soteria Consultants Seyed A. Reihani, Soteria Consultants Donald Wakefield, ABS Consulting, Inc.Janet J. Leavitt, University of New Mexico Approved by: C. Rick Grantom, South Texas Project Steven D. Blossom, South Texas Project South Texas Project Risk-Informed GSI-191 Evaluation Volume 3: CASA Grande Analysis RI-GSI191-V03 Revision 1 The Risk-Informed GSI-191 Closure Pilot Program is an effort piloted by the South Texas Project (STP)Nuclear Operating Company and jointly funded with several other licensees.
It is a collaborative work of teams of experts from industry, academia, and a national laboratory.
In general, all products are developed jointly and reviewed in regularly scheduled (monthly)
Technical Team Meetings and weekly teleconferences as well as in specific review cycles by Independent Oversight (technical evaluation of all materials), STP Nuclear Operating Company project management, and STP Nuclear Operating Company quality management.
The business entities, the main areas of investigation, and the principal investigators of the Pilot Program are summarized below.STP Nuclear Operating Company Project Management, Licensing, Quality Assurance Steve Blossom; Rick Grantom; Ernie Kee; Jamie Paul; Wes Schulz Alion Science and Technology GSI-191 Analysis & Methodology Implementation (GAMI)Tim Sande (Enercon);
Gil Zigler (Enercon);
Austin Glover (Enercon), Clint Shaffer, Joe Tezak (Enercon)The University of New Mexico Chemical Head Loss Experiments (CHLE)Kerry Howe, PhD; Janet Leavitt, PhD (Alion)Los Alamos National Laboratory Containment Accident Stochastic Analysis (CASA) Grande Bruce Letellier, PhD (Alion); Gowri Srinivassan, PhD Soteria Consultants, LLC Independent Oversight Zahra Mohaghegh, PhD; Seyed Reihani, PhD Texas A&M University Thermal Hydraulics (TH)Yassin Hassan, PhD; Rodolfo Vaghetto; Saya Lee, The University of Texas at Austin Uncertainty Quantification (UQ), Jet Formation Elmira Popova, PhD (1962-2012);
David Morton, PhD; Alex Galenko, PhD; Jeremy Tejada, PhD; Erich Schneider, PhD ABS Consulting Probabilistic Risk Assessment (PRA)David Johnson, ScD; Don Wakefield Knf Consulting Services, LLC Location-Specific Failure Damage Mechanism (DM)Karl Fleming; Bengt Lydell (ScandPower)
Page 2 of 260 South Texas Project Risk-Informed GSI-191 Evaluation Volume 3: CASA Grande Analysis RI-GSI191-V03 Revision 1 Revision History Log Revision Date Description 0 1/30/2013 Original document.The following changes were made in this version of the report: 0 Miscellaneous editorial changes 0 Replaced proprietary information related to the fiberglass debris size distribution and fiberglass erosion fractions with references to specific tables that contain the same information in other documents.
- Added a new section describing the information process flow in See Cover CASA Grande.Page P Added a description at the end of the conventional head loss section to clarify that the head loss values calculated with the NUREG/CR-6224 correlation were increased significantly to account for uncertainties in the correlation.
- Replaced informal email reference for shedding parameters with a revised version of the UT technical report and updated parameter values.J L Page 3 of 260 South Texas Project Risk-Informed GSI-191 Evaluation Volume 3: CASA Grande Analysis RI-GSI191-V03 Revision 1 Table of Contents Revision History Log ......................................................................................................................................
3 Table of Contents ..........................................................................................................................................
4 List of Figures ................................................................................................................................................
7 List of Tables ...............................................................................................................................................
10 Definitions and Acronym s ...........................................................................................................................
13 I Introduction
........................................................................................................................................
15 2 Design Input ........................................................................................................................................
21 2.1 General Description of Inputs Required ...............................................................................
21 2.2 Specific Inputs Used ....................................................................................................................
36 2.2.1 Tim ing for Key Plant Response Actions .........................................................................
36 2.2.2 Containm ent Geom etry ................................................................................................
38 2.2.3 LOCA Frequencies
.........................................................................................................
38 2.2.4 Pum p State Frequencies
...............................................................................................
44 2.2.5 Active W ater Volum e .....................................................................................................
46 2.2.6 Pool W ater Level ............................................................................................................
47 2.2.7 Pool Tem perature .........................................................................................................
50 2.2.8 Operating Trains ............................................................................................................
54 2.2.9 ECCS and CSS Flow Rates ................................................................................................
54 2.2.10 Qualified Coatings Quantity ...........................................................................................
58 2.2.11 Unqualified Coatings Quantity .......................................................................................
58 2.2.12 Crud Debris Quantity ....................................................................................................
63 2.2.13 Latent Debris Quantity ...................................................................................................
63 2.2.14 M iscellaneous Debris Quantity .......................................................................................
63 2.2.15 Insulation Destruction Pressure ....................................................................................
63 2.2.16 Insulation Debris Size Distribution
..................................................................................
64 2.2.17 Debris Characteristics
....................................................................................................
64 2.2.18 Initial Pool Chem istry .....................................................................................................
65 2.2.19 Pool pH ................................................................................................................................
66 2.2.20 M etal Quantity ....................................................................................................................
66 2.2.21 Blow dow n Transport Fractions
.......................................................................................
66 2.2.22 W ashdow n Transport Fractions
....................................................................................
67 2.2.23 Pool Fill Transport Fractions
...........................................................................................
68 2.2.24 Recirculation Transport Fractions
..................................................................................
68 2.2.25 Debris Erosion .....................................................................................................................
70 2.2.26 Strainer Geom etry .........................................................................................................
71 2.2.27 Clean Strainer Head Loss ................................................................................................
73 2.2.28 Pum p NPSH M argin .......................................................................................................
74 2.2.29 Strainer Structural M argin .............................................................................................
74 Page 4 of 260 South Texas Project Risk-Informed GS1-191 Evaluation Volume 3: CASA Grande Analysis RI-GSI191-V03 Revision 1 2.2.30 Vortex Air Ingestion
.......................................................................................................
74 2.2.31 Bubble Transport
...........................................................................................................
74 2.2.32 Pum p Gas Lim its ............................................................................................................
74 2.2.33 Fiberglass Penetration
..................................................................................................
74 2.2.34 Decay Heat Curve ............................................................................................................
76 2.2.35 Core Blockage Debris Lim its ...........................................................................................
77 3 Assum ptions ........................................................................................................................................
78 4 M ethodology
.......................................................................................................................................
90 4.1 GSI-191 Analysis Steps ............................................................................................................
94 4.2 Structured Inform ation Process Flow ....................................................................................
96 4.3 Uncertainty Quantification and Propagation
............................................................................
104 4.4 Verification and Validation
.......................................................................................................
104 5 Analysis .............................................................................................................................................
105 5.1 Evaluation Scenarios (PRA Branch Fractions to Populate)
........................................................
105 5.2 Containm ent CAD M odel ..........................................................................................................
108 5.3 LOCA Frequency
........................................................................................................................
130 5.3.1 Relative Probability of Breaks in Specific W eld Categories
...............................................
131 5.3.2 W eld Categories and Coordinates
....................................................................................
141 5.3.3 Statistical Fit of NUREG-1829 LOCA Frequencies
..............................................................
161 5.3.4 Sam ple Epistem ic Uncertainty of LOCA Frequencies
........................................................
162 5.3.5 Distribute Total LOCA Frequency to W eld Locations
........................................................
163 5.3.6 Sam ple Break Sizes at Each W eld Location .......................................................................
163 5.4 Debris Generation
.....................................................................................................................
165 5.4.1 ZOI M odel ..........................................................................................................................
165 5.4.2 Insulation Debris Size Distribution M odel ........................................................................
169 5.4.3 Insulation Debris ...............................................................................................................
170 5.4.4 Qualified Coatings Debris ..................................................................................................
170 5.4.5 Unqualified Coatings Debris ..............................................................................................
171 5.4.6 Latent Debris .....................................................................................................................
171 5.4.7 M iscellaneous Debris ........................................................................................................
172 5.4.8 Debris Characteristics
.......................................................................................................
172 5.5 Chem ical Effects ........................................................................................................................
172 5.5.1 Chem ical Concentration M odel ........................................................................................
173 5.5.2 Solubility Lim it ...................................................................................................................
173 5.5.3 Chem ical Product Type, Form , and Quantity (Pool and Core) ..........................................
173 5.6 Debris Transport
.......................................................................................................................
174 5.6.1 Upstream Blockage ...........................................................................................................
174 5.6.2 Blow dow n Transport
.........................................................................................................
175 5.6.3 W ashdow n Transport
...................................................................................................
175 5.6.4 Pool Fill Transport
.............................................................................................................
175 Page 5 of 260 South Texas Project Risk-Informed GSI-191 Evaluation Volume 3: CASA Grande Analysis RI-GSI191-V03 Revision 1 5.6.5 Recirculation Transport
.....................................................................................................
176 5.6.6 Debris Erosion ...................................................................................................................
176 5.6.7 Strainer Transport
............................................................................................................
176 5.6.8 Tim e-Dependent Debris Arrival M odel .............................................................................
187 5.7 Strainer Head Loss ....................................................................................................................
189 5.7.1 Clean Strainer Head Loss ...................................................................................................
189 5.7.2 Conventional Debris Head Loss M odel .............................................................................
191 5.7.3 Chem ical Debris Head Loss M odel ....................................................................................
199 5.7.4 Strainer Head Loss .............................................................................................................
203 5.7.5 Acceptance Criterion:
NPSH M argin M odule ....................................................................
204 5.7.6 Acceptance Criterion:
Structural M argin ..........................................................................
210 5.8 Air Intrusion
..............................................................................................................................
210 5.8.1 Vortex Form ation ..............................................................................................................
210 5.8.2 Degasification
....................................................................................................................
211 5.8.3 Gas Transport and Accum ulation ......................................................................................
216 5.8.4 Acceptance Criterion:
Pum p Gas Void Lim its ....................................................................
220 5.9 Debris Penetration
....................................................................................................................
220 5.10 Ex-Vessel Dow nstream Effects ..................................................................................................
226 5.10.1 Pum p, Valve, Com ponent W ear ........................................................................................
226 5.10.2 System and Com ponent Clogging/Blockage
.....................................................................
227 5.11 In-Vessel Dow nstream Effects ..................................................................................................
228 5.11.1 Fuel Rod Debris Deposition (LOCADM ) .............................................................................
228 5.11.2 Core Blockage Scenarios
...................................................................................................
229 5.11.3 Decay Heat Boil-Off Flow Rate ..........................................................................................
237 5.11.4 Tim e-Dependent Core Debris Accum ulation ....................................................................
239 5.11.5 Acceptance Criteria:
Debris Loads ....................................................................................
240 5.12 Boron Precipitation
...................................................................................................................
240 5.12.1 Tim e-Dependent Core Debris Accum ulation ....................................................................
242 5.12.2 Acceptance Criteria:
Debris Loads ....................................................................................
242 5.13 Param etric Evaluations
.............................................................................................................
242 6 Results ...............................................................................................................................................
245 7 Conclusions
.......................................................................................................................................
254 8 References
........................................................................................................................................
255 Appendix 1: CASA Grande Input Deck .......................................................................................................
1-1 Page 6 of 260 South Texas Project Risk-Informed GSI-191 Evaluation Volume 3: CASA Grande Analysis RI-GSI191-V03 Revision 1 List of Figures Figure 1.1 -CASA Grande input variables
.............................................................................................
18 Figure 1.2 -CASA Grande calculation m odules ....................................................................................
19 Figure 1.3 -CASA G rande link to PRA ...................................................................................................
20 Figure 2.1.1 -Illustration of input variable relationships for debris generation analysis .....................
26 Figure 2.1.2 -Illustration of input variable relationships for chemical effects analysis .......................
28 Figure 2.1.3 -Illustration of input variable relationships for debris transport analysis (Part 1) ...........
30 Figure 2.1.4 -Illustration of input variable relationships for debris transport analysis (Part 2) ...........
31 Figure 2.1.5 -Illustration of input variable relationships for strainer head loss analysis .....................
33 Figure 2.1.6 -Illustration of input variable relationships for gas intrusion analysis .............................
34 Figure 2.1.7 -Illustration of input variable relationships for debris penetration and core blockage a n a ly sis ........................................................................................................................................................
3 6 Figure 2.2.1 -RWST injection mass probability distribution
.................................................................
47 Figure 2.2.2 -Nominal containment pool temperature profiles ...........................................................
51 Figure 2.2.3 -Temperature profiles implemented in CASA Grande .....................................................
54 Figure 2.2.4 -Total SI flow rate vs. break size .......................................................................................
56 Figure 2.2.5 -Epoxy failure fraction probability distribution
...............................................................
59 Figure 2.2.6 -IOZ failure fraction probability distribution
...................................................................
60 Figure 2.2.7 -Alkyd and baked enamel failure fraction probability distribution
...................................
61 Figure 2.2.8 -STP strainer Photo 1 (before protective grating was installed)
.......................................
72 Figure 2.2.9 -STP strainer Photo 2 (after protective grating was installed)
..........................................
72 Figure 2.2.10 -STP strainer Photo 3 .....................................................................................................
72 Figure 2.2.11 -STP strainer Photo 4 .....................................................................................................
73 Figure 4.1 -Example of realistic probability distribution for an input variable .....................................
91 Figure 4.2 -Risk-inform ed GSI-191 resolution path .............................................................................
93 Figure 4.2.1 -Illustration of a hypothetical DEGB spherical ZOI truncated by a wall ...........................
98 Figure 4.2.2 -Illustration of the processes local to the ECCS screen .......................................................
100 Figure 4.2.3 -Illustration of the flow paths in the reactor vessel ............................................................
101 Figure 4.2.4 -Illustration of sum p failure criteria ................................................................................
102 Figure 4.2.5 -Illustration of processes local to the strainer with a direct impact on the performance th re sh o ld s .........................................................................
.......................................................................
103 Figure 5.2.1 -Cross-section of steam generator compartment with Loops B and C ...............................
108 Figure 5.2.2 -Close-up view of steam generator compartment with Loops B and C ..............................
109 Figure 5.2.3 -O perating deck (Elevation 68'-0") ......................................................................................
110 Figure 5.2.4 -Piping and equipm ent (View 1) ..........................................................................................
111 Figure 5.2.5 -Piping and equipm ent (View 2) ..........................................................................................
112 Figure 5.2.6 -Steam generator compartment floor (Elevation 19'0") .....................................................
113 Figure 5.2.7 -Plan view of containment floor (Elevation
-11'3") .............................................................
114 Figure 5.2.8 -Isometric view of containment floor (Elevation
-11'3") ....................................................
115 Page 7 of 260 South Texas Project Risk-Informed GSI-191 Evaluation Volume 3: CASA Grande Analysis RI-GSI191-V03 Revision 1 Figure 5.2.9 -Plan view of m ajor piping and equipm ent .........................................................................
116 Figure 5.2.10 -Section view of RCS Loop D (left) and Loop A (right) .......................................................
117 Figure 5.2.11 -Section view of RCS Loop D (left) and Loop C (right) .......................................................
118 Figure 5.2.12 -Nukon insulation on piping, pressurizer, pumps, and heat exchangers
..........................
119 Figure 5.2.13 -Thermal-W rap insulation on steam generators
...............................................................
120 Figure 5.2.14 -Microtherm insulation in secondary shield wall penetrations
........................................
121 Figure 5.2.15 -Lead blankets on pipes .....................................................................................................
122 Figure 5.2.16 -Welds representing potential LOCA break locations (View 1) .........................................
123 Figure 5.2.17 -Welds representing potential LOCA break locations (View 2) .........................................
123 Figure 5.2.18 -Currently installed ECCS strainers
....................................................................................
124 Figure 5.2.19 -Illustration of additional insulation modeled at hanger and valve locations
..................
125 Figure 5.2.20 -Illustration of work points used to identify location of welds, hangers, and valves ....... 126 Figure 5.2.21 -Exam ple of CAD m odel text data output .........................................................................
127 Figure 5.2.22 -Concrete walls and floors exported from CAD model in STL format ...............................
128 Figure 5.2.23 -Grating exported from CAD model in STL format ............................................................
129 Figure 5.2.24 -Geometry of piping and equipment insulation in CASA Grande .....................................
130 Figure 5.3.1 -Locations of Category 6B welds that were modeled .........................................................
144 Figure 5.3.2 -Illustration of bounded Johnson fit for NUREG-1829 break frequencies
..........................
161 Figure 5.3.3 -Illustration of LOCA frequency vs. break size for 62nd percentile
......................................
163 Figure 5.3.4 -Example of non-uniform stratified sampling strategy for one weld case ..........................
165 Figure 5.4.1 -Illustration of 17D Nukon ZOI for a 31" DEGB ...................................................................
167 Figure 5.4.2 -Illustration of 17D Nukon ZOI for a 6" side-wall break ......................................................
168 Figure 5.4.3 -Illustration of 17D Nukon ZOI for a 2" side-wall break ......................................................
168 Figure 5.4.4 -Illustration of sub-zones used for fiberglass debris size distribution
................................
169 Figure 5.4.5 -Distribution of potential fiberglass debris quantities
........................................................
170 Figure 5.6.1 -Photograph of 30-inch vent hole in secondary shield wall ................................................
175 Figure 5.6.2 -Example logic tree for LDFG fines (SG compartment LBLOCA) ..........................................
178 Figure 5.6.3 -Example logic tree for LDFG small pieces (SG compartment LBLOCA) ..............................
179 Figure 5.6.4 -Example logic tree for LDFG large pieces (SG compartment LBLOCA) ..............................
180 Figure 5.6.5 -Example logic tree for Microtherm fines (SG compartment LBLOCA) ...............................
180 Figure 5.6.6 -Example logic tree for crud fines (SG compartment LBLOCA) ...........................................
181 Figure 5.6.7 -Example logic tree for qualified coatings fines (SG compartment LBLOCA) ......................
182 Figure 5.6.8 -Example logic tree for unqualified alkyd coatings fines (SG compartment LBLOCA) ........ 183 Figure 5.6.9 -Example logic tree for unqualified epoxy coatings fines (SG compartment LBLOCA) ....... 183 Figure 5.6.10 -Example logic tree for unqualified epoxy coatings fine chips (SG compartment LBLOCA)..................................................................................................................................................................
1 8 4 Figure 5.6.11 -Example logic tree for unqualified epoxy coatings small chips (SG compartment LBLOCA)..................................................................................................................................................................
1 8 4 Figure 5.6.12 -Example logic tree for unqualified epoxy coatings large chips (SG compartment LBLOCA)..................................................................................................................................................................
1 8 5 Page 8 of 260 South Texas Project Risk-Informed GSI-191 Evaluation Volume 3: CASA Grande Analysis RI-GSI191-V03 Revision 1 Figure 5.6.13 -Example logic tree for unqualified epoxy coatings curled chips (SG compartment LBLOCA)..................................................................................................................................................................
1 8 5 Figure 5.6.14 -Example logic tree for unqualified IOZ coatings fines (SG compartment LBLOCA) .........
186 Figure 5.6.15 -Example logic tree for latent fines (SG compartment LBLOCA) .......................................
186 Figure 5.6.16 -Illustration of tim e-dependent transport
........................................................................
188 Figure 5.7.1 -Clean strainer head loss curve fit with both viscous and inertial terms ............................
190 Figure 5.7.2 -Clean strainer head loss curve fit with only inertial term ..................................................
191 Figure 5.7.3 -Exponential probability density function for chemical effects bump-up factors applied to S B LO C A s ....................................................................................................................................................
2 01 Figure 5.7.4 -Exponential probability density function for chemical effects bump-up factors applied to M B LO C A s ...................................................................................................................................................
2 0 2 Figure 5.7.5 -Exponential probability density function for chemical effects bump-up factors applied to LB LO C A s ....................................................................................................................................................
2 0 3 Figure 5.7.6- Typical sample of sump-strainer head loss histories generated under the assumption of exponential chemical effects factor and artificial head-loss inflation
......................................................
204 Figure 5.7.7 -Illustration of parameters that affect pump NPSH ............................................................
205 Figure 5.7.8 -Schematic of STP ECCS sum p suction piping ......................................................................
207 Figure 5.8.1 -Isom etric view of ECCS strainer .........................................................................................
217 Figure 5.8.2 -Cross-section view of ECCS strainer and sump pit .............................................................
217 Figure 5.8.3 -Illustration of air bubble accum ulation and venting ..........................................................
220 Figure 5.9.1 -Illustration of direct passage and shedding .......................................................................
221 Figure 5.9.2 -Illustration of time-dependent parameters associated with debris accumulation on the stra ine r a n d co re .......................................................................................................................................
2 2 2 Figure 5.11.1 -Deposit growth process assumed by LOCADM when core is boiling (62) .......................
229 Figure 5.11.2 -Illustration of RCS at STP ..................................................................................................
230 Figure 5.11.3 -Large or medium hot leg break during cold leg injection with partial core blockage ..... 231 Figure 5.11.4 -Large or medium hot leg break during hot leg injection
.................................................
233 Figure 5.11.5 -Large or medium cold leg break during cold leg injection with partial core blockage .... 234 Figure 5.11.6 -Large or medium cold leg break during hot leg injection
................................................
235 Figure 5.11.7- Sm all hot leg break during cold leg injection
...................................................................
236 Figure 5.11.8 -Tim e-dependent boil-off flow rate ..................................................................................
239 Figure 5.12.1 -Amorphous precipitate formation on heated surface (94) .............................................
241 Figure 5.13.1- STP ECCS strainer prior to upgrade ..................................................................................
243 Figure 6.1 -Linear-linear interpolation of bounded Johnson extrema (solid) with non-uniform stratified random break-size profiles (dashed) ........................................................................................................
248 Figure 6.2 -Empirical distribution of total failure probability for Case 43 (one train operable) based on five discrete samples of the NUREG-1829 break-frequency uncertainty envelope .................................
250 Page 9 of 260 South Texas Project Risk-Informed GSI-191 Evaluation Volume 3: CASA Grande Analysis RI-GSI191-V03 Revision 1 List of Tables Table 2.1.1 -General input variables used in multiple aspects of the analysis .....................................
22 Table 2.1.2 -Input variables used primarily in debris generation analysis ..........................................
25 Table 2.1.3 -Input variables used primarily in chemical effects analysis ............................................
27 Table 2.1.4 -Input variables used primarily in debris transport analysis ............................................
28 Table 2.1.5 -Input variables used primarily in strainer head loss analysis ..........................................
31 Table 2.1.6 -Input variables used primarily in gas intrusion analysis ...................................................
33 Table 2.1.7 -Input variables used primarily in debris penetration and in-vessel effects analysis ..... 34 Table 2.2.1 -Sum p sw itchover tim e .....................................................................................................
38 Table 2.2.2 -NUREG-1829 PWR current-day LOCA frequencies and fitted Johnson parameters
...... 39 Table 2.2.3 -Relative frequencies vs. break size for hot leg, SG inlet, cold leg, and surge line welds (Categories 1A through 4D) ......................................................................................................
40 Table 2.2.4 -Relative frequencies vs. break size for pressurizer and small bore line welds (Categories 5A th ro u g h 6 B ) .................................................................................................................................................
4 1 Table 2.2.5 -Relative frequencies vs. break size for safety injection and recirculation line welds (Catego ries 7A th ro ugh 7L) .........................................................................................................................
4 2 Table 2.2.6 -Relative frequencies vs. break size for accumulator injection and CVCS line welds (Catego ries 7M through 8F) ........................................................................................................................
43 Table 2.2.7 -Frequency of success pump combination states ............................................................
44 Table 2.2.8 -RWST injection mass probability distribution inputs .....................................................
47 Table 2.2.9 -Volume of water in the RCS during recirculation
.............................................................
49 Table 2.2.10 -Range of water volumes implemented in CASA Grande .................................................
50 Table 2.2.11 -Fitting results for nominal temperature profiles ..........................................................
52 Table 2.2.12- Total SI flow rates .............................................................................
.........
55 Table 2.2.13 -Containm ent spray flow rates .........................................................................................
57 Table 2.2.14 -Quantity of qualified coatings debris .............................................................................
58 Table 2.2.15 -Quantity and location of potentially transportable unqualified coatings debris ...........
58 Table 2.2.16 -Epoxy failure fraction probability distribution inputs ...................................................
59 Table 2.2.17 -IOZ failure fraction probability distribution inputs ........................................................
59 Table 2.2.18 -Alkyd and baked enamel failure fraction probability distribution inputs .......................
60 Table 2.2.19 -Time dependent failure fraction of unqualified coatings ......................
62 Table 2.2.20 -Unqualified epoxy debris size distribution
....................................................................
63 Table 2.2.21 -Q uantity of latent debris ................................................................................................
63 Table 2.2.22 -Input variables used primarily in debris penetration and core blockage analysis ...... 64 Table 2.2.23 -M aterial properties of debris .........................................................................................
65 Table 2.2.24 -Blowdown transport fractions according to break location .........................................
67 Table 2.2.25 -Washdown transport fractions according to spray initiation
.......................................
68 Table 2.2.26 -Pool fill transport fractions according to break location ...............................................
68 Table 2.2.27 -Recirculation pool transport fractions according to break size and location (insulation)
.. 69 Page 10 of 260 South Texas Project Risk-Informed GSI-191 Evaluation Volume 3: CASA Grande Analysis RI-GSI191-V03 Revision 1 Table 2.2.28 -Recirculation transport fractions according to break size and location (coatings, latent d e b ris, crud, d irt/d ust) ................................................................................................................................
70 Table 2.2.29 -Clean strainer head loss ................................................................................................
73 Table 2.2.30 -Fitted filtration parameters for test module .................................................................
75 Table 2.2.31 -Fitted filtration parameters for each ECCS strainer ........................................................
75 Table 2.2.32 -Fitted shedding param eters ...........................................................................................
76 Table 2.2.33 -Decay heat generation rate based on 1979 ANS plus 2 sigma uncertainty
...................
76 Table 3.1 -Strainer debris accumulation and approach velocity comparison
.....................................
81 Table 3.2 -Strainer debris accumulation and approach velocity comparison for CS pump failures8
........ 82 Table 3.3 -Core debris accumulation for various pump failures ..........................................................
82 Table 5.1.1 -Bounding or representative cases for highest frequency pump combination states .........
107 Table 5.3.1 -Description of w eld categories
............................................................................................
132 Table 5.3.2 -Interpolated relative frequencies vs. break size for hot leg, SG inlet, cold leg, and surge line w elds (Categories 1A through 4D ) ............................................................................................................
135 Table 5.3.3 -Interpolated relative frequencies vs. break size for pressurizer and small bore line welds (Catego ries 5A thro ugh 6A ) ......................................................................................................................
136 Table 5.3.4 -Interpolated relative frequencies vs. break size for small bore and safety injection and recirculation line w elds (Categories 6B through 7J) .................................................................................
137 Table 5.3.5 -Interpolated relative frequencies vs. break size for safety injection and recirculation, accumulator injection, and CVCS line welds (Categories 7K through 8F and total frequencies)
.............
138 Table 5.3.6 -Total relative frequency vs. break size ................................................................................
139 Table 5.3.7 -Relative contribution of each weld category to total LOCA frequencies
............................
140 Table 5.3.8 -Comparison of LOCA frequency report and CAD model pipe sizes and weld counts .........
142 Table 5.3.9 -Weld data from component database and CAD model ......................................................
145 Table 5.3.10 -Example calculation of LOCA frequencies vs. break size for 6 2 nd Percentile
....................
162 Table 5.6.1 -Tim e-dependent transport
..................................................................................................
187 Table 5.7.1 -Clean strainer head loss evaluation
....................................................................................
190 Table 5.7.2 -Head loss characteristics for fibrous debris ........................................................................
195 Table 5.7.3 -Head loss characteristics for non-fibrous debris .................................................................
195 Table 5.7.4 -Exponential probability distribution parameters applied to chemical effects bump-up factors for each LO CA category ................................................................................................................
200 Table 5.8.1 -Semi-empirical correlation parameters to calculate Henry's constants in aqueous solvent (8 5 ) ............................................................................................................................................................
2 1 2 Table 5.11.1 -Decay heat generation rate based on 1979 ANS plus 2 sigma uncertainty
......................
238 Table 5.13.1 -Comparison of mean LBLOCA conditional failure probabilities before and after ECCS straine r re p lace m e nt ................................................................................................................................
24 4 Table 6.1 -Mean LBLOCA conditional failure probabilities for five states of pump availability
..............
246 Table 6.2 -Distribution of total conditional failure for LBLOCAs under Case 43 (single train operable) 249 Table 6.3 -Cold leg split fractions conditioned on LOCA category for Case 43 .......................................
251 Table 6.4 -Partial itemization of break events that lead to failure for plant state Case 43 ....................
252 Page 11 of 260 South Texas Project Risk-Informed GSI-191 Evaluation Volume 3: CASA Grande Analysis RI-GSI191-V03 Revision 1 Page 12 of 260 South Texas Project Risk-Informed GSI-191 Evaluation Volume 3: CASA Grande Analysis RI-GSI191-V03 Revision 1 Definitions and Acronyms ALOOH Aluminum Oxy-Hydroxide ARL Alden Research Laboratory BC Branch Connection BEP Best Efficiency Point B-F Bimetallic Welds B-J Single Metal Welds BWR Boiling Water Reactor CAD Computer Aided Drafting CASA Containment Accident Stochastic Analysis CCDF Complementary Cumulative Distribution Function CCW Component Cooling Water CDF Core Damage Frequency CHLE Chemical Head Loss Experiments CS Containment Spray CSHL Clean Strainer Head Loss CSS Containment Spray System CVCS Chemical Volume Control System D&C Design and Construction Defects DEGB Double Ended Guillotine Break DM Degradation Mechanism ECC Emergency Core Cooling ECCS Emergency Core Cooling System EOP Emergency Operating Procedure EPRI Electric Power Research Institute ESF Engineered Safety Feature FA Fuel Assembly GL 08-01 Generic Letter 2008-01 GSI-191 Generic Safety Issue 191 HHSI High Head Safety Injection HLSO Hot Leg Switchover ICET Integrated Chemical Effects Tests IGSCC Intergranular Stress Corrosion Cracking LBLOCA Large Break Loss of Coolant Accident LDFG Low Density Fiberglass LERF Large Early Release Frequency LHSI Low Head Safety Injection LOCA Loss of Coolant Accident MBLOCA Medium Break Loss of Coolant Accident NPSH Net Positive Suction Head Page 13 of 260 South Texas Project Risk-Informed GSI-191 Evaluation Volume 3: CASA Grande Analysis RI-GSI191-V03 Revision 1 NRC Nuclear Regulatory Commission OD Outer Diameter PDF Probability Density Function PRA Probabilistic Risk Assessment PWR Pressurized Water Reactor PWROG Pressurized Water Reactor Owner's Group PWSCC Primary Water Stress Corrosion Cracking RCS Reactor Coolant System RHR Residual Heat Removal RI-ISI Risk-Informed In-Service Inspection RMI Reflective Metal Insulation RWST Refueling Water Storage Tank SAS Sodium Aluminum Silicate SBLOCA Small Break Loss of Coolant Accident SC Stress Corrosion SI Safety Injection SIR Safety Injection and Recirculation SRM Staff Requirements Memorandum STP South Texas Project STPNOC South Texas Project Nuclear Operating Company TAMU Texas A&M University TF Thermal Fatigue TGSCC Transgranular Stress Corrosion Cracking TSC Technical Support Center TSP Trisodium Phosphate UNM University of New Mexico USI A-43 Unresolved Safety Issue A-43 UT University of Texas (Austin)V&V Verification and Validation VF Vibration Fatigue WCAP Westinghouse Commercial Atomic Power ZOI Zone of Influence Page 14 of 260 South Texas Project Risk-Informed GSI-191 Evaluation Volume 3: CASA Grande Analysis RI-GSI191-V03 Revision 1 1 Introduction The emergency core cooling system (ECCS) and containment spray system (CSS) in a pressurized water reactor (PWR) are designed to safely shutdown the plant following a loss of coolant accident (LOCA) in accordance with 10CFR50.46.
The assurance of long term core cooling in PWRs following a LOCA has a long history dating back to the Nuclear Regulatory Commission (NRC) studies of the mid 1980s associated with Unresolved Safety Issue (USI) A-43. Results of the NRC research on boiling water reactor (BWR) ECCS suction strainer blockage of the early 1990s identified new phenomena and failure modes that were not considered in the resolution of USI A-43. As a result of these concerns, Generic Safety Issue (GSI) 191 was identified in September 1996 related to debris clogging of the ECCS sump suction strainers at PWRs. Although plants have taken steps to prevent strainer clogging (by increasing the screen area, for example), satisfactory closure of this issue has proved elusive due to long term cooling issues and the effect of chemical precipitates on head loss. Previous investigators have identified bounding scenarios using conservative inputs, methods, and acceptance criteria.
The acceptance criteria are applied in a "pass/fail" fashion that ignores the risk significance.
That is, if the results are acceptable, the issue has been resolved.
Otherwise, it is necessary to either redo the analysis with partial relaxation of analytical conservatisms or perform additional plant modifications to ensure that the acceptance criteria are met.A sudden break in the reactor coolant system (RCS) piping at a PWR would result in a high energy, two-phase jet. Depending on the size and location of the break, it is possible for the jet to destroy a large quantity of insulation on nearby piping and equipment.
During the RCS blowdown phase, some of the insulation debris may be blown to upper containment and some may be blown to lower regions of the containment.
Per plant design, the ECCS and CSS would be automatically initiated, drawing flow from the refueling water storage tank (RWST). The CSS would wash some debris from upper containment down to the containment floor. Debris on the containment floor could be transported by the high-velocity sheeting flow as the pool fills. Some debris may be transported into inactive cavities below the containment floor (such as the reactor cavity), or directly to the ECCS sump strainers as the sump cavities fill. After the RWST has been depleted, the ECCS and CSS pumps would be automatically switched over to recirculation.
Some of the debris in the containment pool would be transported to the ECCS sumps where it would accumulate on the strainers.
Some of the fine debris (particulate and fiberglass fines)would pass through (or penetrate) the strainer.As debris collects on the strainer, the head loss across the strainer would rise. Corrosion of various containment metals, and dissolution of insulation debris and other materials in the buffered and borated containment pool may result in the formation of chemical precipitates.
These precipitates can accumulate on the strainer debris beds increasing the overall head loss. Some of the chemical precipitates may also penetrate the strainer.
If the head loss across the strainer exceeds either the net Page 15 of 260 South Texas Project Risk-Informed GSI-191 Evaluation Volume 3: CASA Grande Analysis RI-GSI191-V03 Revision 1 positive suction head (NPSH) margin for the safety injection (SI) system, or the strainer structural margin, long-term core cooling may be compromised.
Debris that penetrates through the strainer can also cause downstream issues including blockage or wear of various downstream components, or more significantly blockage of the fuel channels within the reactor core.The assurance of long-term post-LOCA core cooling must be fully addressed as required by the NRC in Generic Letter 2004-02 (1). All U.S. PWRs have worked through the required analyses using deterministic approaches.
In 2006, the NRC commissioners issued a staff requirements memorandum (SRM) directing the staff and industry to make a concerted effort to look at resolution of the GSI-191 issue holistically (2). This proved to be challenging since the analyses were performed using bounding methods. Although there were known conservatisms in the analyses, there was no method for quantifying the overall margin associated with the conservatisms so that the effects of best-estimate assumptions could be put into proper perspective and compared to the conservative assumptions to holistically determine the overall level of margin.In 2010, due to the ongoing challenges of resolving GSI-191, the NRC commissioners directed the staff to consider new and innovative resolution approaches (3). One of the approaches included in the SRM was the option of addressing GSI-191 using a risk-informed approach.
In 2011, South Texas Project (STP)initiated a three-year effort as a pilot plant to define and implement a risk-informed approach to resolve GSI-191. A software tool called CASA Grande' was developed to analyze the accident sequences in a realistic time-dependent manner with uncertainty propagation to determine the probabilities of various failures potentially leading to core damage from a spectrum of location-specific pipe breaks (i.e. LOCAs)for input into STP's plant-specific probabilistic risk assessment (PRA). The specific failure modes that need to be considered are: 1. Strainer head loss exceeds the NPSH margin for the pumps causing some or all of the ECCS and CSS pumps to fail.2. Strainer head loss exceeds the strainer structural margin causing the strainer to fail, which could subsequently result in larger quantities and larger sizes of debris being ingested into the ECCS and CSS.3. Air intrusion exceeds the limits of the ECCS and CSS pumps causing degraded pump performance or complete failure due to gas binding.4. Debris penetration exceeds ex-vessel effects limits causing a variety of potential equipment and component failures due to wear or clogging.5. Debris penetration exceeds in-vessel effects limits resulting in partial or full core blockage with insufficient flow to cool the core.1 CASA is an acronym for Containment Accident Stochastic Analysis Page 16 of 260 South Texas Project Risk-Informed GSI-191 Evaluation Volume 3: CASA Grande Analysis RI-GSI191-V03 Revision 1 6. Buildup of oxides, crud, LOCA-generated debris, and chemical precipitates on fuel cladding exceeds the limits for heat transfer resulting in unacceptably high peak cladding temperatures.
- 7. Boron concentration in the core exceeds the solubility limit leading to boron precipitation and subsequently resulting in unacceptable flow blockage or impaired heat removal.Failure Modes 4 and 6 have been conservatively addressed as part of the previous deterministic evaluation for STP with no issues of concern (see Sections 5.10 and 5.11.1), and are therefore not explicitly modeled in CASA Grande. The remaining failure modes are explicitly modeled.This report provides a full description of the CASA Grande software including the input parameters, assumptions, methodology, and results of the STP analysis.
It also provides a description of the software verification and validation (V&V) and the parametric evaluations that have been performed.
Figure 1.1 and Figure 1.2 illustrate the input variables and analytical modules used for CASA Grande, and Figure 1.3 illustrates the link between CASA Grande and the PRA.Page 17 of 260 South Texas Project Risk-Informed GSI-191 Evaluation Volume 3: CASA Grande Analysis RI-GSI191-V03 Revision 1 General Inputs* Accident Time* Active Water Volume* Pool Water Level* Containment Pressure* Pool Temperature
- Operating Trains* Spray Flow Rate* Injection Flow Rate* Sump Flow Rate Debris Generation Inouts" LOCA Frequency" Insulation Location" Qualified Coatings Location" Unqualified Coatings Location/Failure
- Latent Debris Quantity" Miscellaneous Debris Quantity" Destruction Pressure" Size Distribution
- Debris Density Debris Transport Inputs* Grating Location* Blowdown Transport* Washdown Transport* Pool Fill Transport* Recirculation Transport* Debris Erosion-.. ..... ..... .-.. ....I Chemical Effects Inputs" Initial Pool Chemistry" Acid Formation" Pool pH" Metal Quantity* Material Release Rates* Solubility Limits CASA Grande I Strainer Head Loss Inputs" Strainer Height" Strainer Area" Strainer Interstitial Volume" Clean Strainer Head Loss" NPSH Margin" Structural Margin 10 I Debris Penetration Inputs" Filtration Efficiency" Shedding Parameters I I: Air Intrusion Inputs Vortex Air Ingestion Pump Gas Limits qm.....I I Core Blockage Inputs* Reactor Inlet Temperature" Driving Head* Required Core Flow Rate Boron Precipitation Inputs* Boron Solubility Limit" Boil-off Rate" RWST Boron Concentration" Acceptable Fiber Quantity Figure 1.1 -CASA Grande input variables Page 18 of 260 South Texas Project Risk-Informed GSI-191 Evaluation Volume 3: CASA Grande Analysis RI-GS1191-V03 Revision 1 CASA Grande I I I I WI I I I I//1%Pump NPSH Margin Module-%- -----I l --------J Figure 1.2 -CASA Grande calculation modules Page 19 of 260 South Texas Project Risk-Informed GSI-191 Evaluation Volume 3: CASA Grande Analysis RI-GSI191-V03 Revision 1 I PRAA Scenarios*S/M/L Break* rain/Pump Failure CASA Grande I I Strainer Head Loss Pump Failure (Exceed NPSH Margin)Strainer Failure (Exceed Structural Margin)I.Air Intrusion Pump Failure (Exceed Pump Gas Void Limits)IU ...I.Core Blockage Core Damage (Insufficient Core Flow)I.Boron Precipitation Core Damage (Insufficient Core Flow)U I Output Analyzer" Compare results to acceptance criteria to determine failure event distributions" Organize results in S/M/L categories for input in PRA* Identify significant parameters and phenomena resulting in failure I I I I I I I I I I I I/-------I S PRA Branch Fractions S/M/L Break Train/Pump Failure Figure 1.3 -CASA Grande link to PRA Page 20 of 260 South Texas Project Risk-Informed GSI-191 Evaluation Volume 3: CASA Grande Analysis RI-GSI191-V03 Revision 1 2 Design Input A wide range of input variables are used in the various GSI-191 analysis areas. In some cases, the input may consist of a single value, in other cases the input may have a probability distribution or change over time. Some inputs must be entered into CASA Grande as part of the input deck (e.g. containment pool temperature profiles), while other inputs may be calculated within the software (e.g. strainer head loss, which is directly calculated and then used as an input for the degasification calculation).
Section 2.1 provides a general description of the relationship between the various input parameters, and Section 2.2 provides a description of the actual inputs used in the STP analysis.The detailed analyses required to develop each of the design inputs are described in the referenced documents in Section 2.2. The majority of the significant input variables that were developed as part of the STP risk-informed GSI-191 evaluation project were developed under the following topical areas:* Containment CAD Model (4)* Thermal Hydraulics Modeling (5; 6)" LOCA Frequency Evaluation (7; 8; 9)" Jet Formation Modeling (10)" Coatings and Crud Debris Calculations (11; 12; 13)" Water Volume/Level Calculation (14)" Chemical Effects Testing (15; 16; 17; 18; 19; 20; 21; 22)* Debris Transport Calculation (23)* Strainer Head Loss Testing (24)* NPSH Calculation (25)* Strainer Penetration Testing (26; 27; 28; 8)* In-vessel Effects Evaluation (29)2.1 General Description of Inputs Required Table 2.1.1 through Table 2.1.7 list the design input variables that go into a GSI-191 evaluation.
They also show the relationship between other input and output variables, and whether the conservative direction is represented by a high or low value. Note that in many cases, input values may affect multiple outputs where in one situation it is conservative to assume a low value and in another situation it is conservative to assume a high value. Figure 2.1.1 through Figure 2.1.7 illustrate how the various input variables tie together in CASA Grande. Some of the CASA Grande modules and inputs have not been implemented in CASA Grande at this time. These inputs/modules are shown on the figures as boxes with dashed lines.Page 21 of 260 South Texas Project Risk-Informed GSI-191 Evaluation Volume 3: CASA Grande Analysis RI-GSI191-V03 Revision 1 Table 2.1.1 -General input variables used in multiple aspects of the analysis Design Input Conservative Preceding Direct-Input Proceeding Direct- Comments Variable Direction Variables Output Variables I Accident Time N/A N/A Unqualified Coatings Failure, Debris Quantity, Acid Formation, Pool pH, Pool Temperature, Solubility Limits, Material Release Rates, Precipitant Concentrations, Precipitate Quantity, Precipitate Form, Spray Flow Rate, Injection Flow Rate, Sump Flow Rate, Washdown Transport, Operating Trains, Pool Turbulence, Pool Velocity, Debris Erosion, Strainer Transport, Containment Pressure, Containment Temperature, Strainer Approach Velocity, Debris Bed Thickness, Clean Strainer Head Loss, Strainer Head Loss, NPSH Required, NPSH Available, NPSH Margin, Degasification, Gas Void Fraction, Heat Exchanger Temperature Drop, Reactor Inlet Temperature, Debris Penetration, Driving Head, Incore Head Loss, Core Flow Rate, Required Core Flow Rate, Boron Precipitation, Sump Failure, In-Vessel Failure Break Location N/A LOCA Frequency Debris Quantity, Debris Size Distribution, Blowdown Transport, Recirculation Transport, Driving Head, Core Flow Rate Break Size '1 LOCA Frequency Containment Pressure, Containment Temperature, Pool Temperature, ZOI Size, Driving Head, Core Flow Rate Page 22 of 260 South Texas Project Risk-Informed GSI-191 Evaluation Volume 3: CASA Grande Analysis RI-GSI191-V03 Revision 1 Design Input Conservative Preceding Direct-Input Proceeding Direct- Comments Variable Direction Variables Output Variables RCS Pressure ' N/A RCS Volume, ZOI Size, Boil-off Rate RCS '" N/A RCS Volume, ZOI Size Temperature RWST Injection
' N/A Total Water Volume, Volume Initial Pool Chemistry RCS Volume t, RCS Pressure, RCS Total Water Volume, Temperature Initial Pool Chemistry Accumulator N/A Total Water Volume, Injection Initial Pool Chemistry Volume Total Water '" RWST Injection Active Water Volume Volume Volume, RCS Volume, Accumulator Injection Volume Inactive Cavity '1 4 N/A Active Water Volume, Volume Pool Fill Transport Active Water t _J/ Total Water Volume, Pool Water Level, Volume Inactive Cavity Volume Precipitant Concentrations Transitory
'1' See comments Pool Water Level Includes volume of Water Volume water in RCS, ECCS suction and containment spray piping, sprays migrating to pool, condensation on walls, etc.Pool Water ' Active Water Volume, Pool Turbulence, Pool Level Transitory Water Velocity, NPSH Available, Volume Vortex Air Ingestion, Degasification Containment
'1' N/A Containment Pressure Containment may not Leakage be isolated in some scenarios RWST t" N/A Containment Temperature Temperature, Pool Temperature Heat Sink '"'4 N/A Containment Temperature Temperature, Pool Temperature Fan Cooler Flow '" 4 N/A Containment Rate Temperature, Pool Temperature Page 23 of 260 w1.NNWW South Texas Project Risk-Informed GSI-191 Evaluation Volume 3: CASA Grande Analysis RI-GSI191-V03 Revision 1 Design Input Conservative Preceding Direct-Input Proceeding Direct- Comments Variable Direction Variables Output Variables Containment Break Size, Containment Pressure Containment Leakage, Temperature, NPSH Containment Available, Degasification Temperature, Accident Time Containment Break Size, RWST Containment Pressure, Temperature Temperature, Pool Pool Temperature Temperature, Heat Sink Temperature, Fan Cooler Flow Rate, Spray Flow Rate, Injection Flow Rate, Containment Pressure, Accident Time Pool "1" Break Size, RWST Containment Temperature Temperature, Temperature, Material Containment Release Rates, Solubility Temperature, Heat Sink Limits, Settling Velocity, Temperature, Fan Strainer Head Loss, NPSH Cooler Flow Rate, Spray Available, Degasification, Flow Rate, Injection Heat Exchanger Flow Rate, Accident Temperature Drop, Time Reactor Inlet Temperature Operating N/A Spray Flow Rate, Injection Trains Flow Rate, Sump Flow Rate, Recirculation Transport, Strainer Approach Velocity, Debris Bed Thickness Spray Flow Rate ' Operating Trains, Containment Accident Time Temperature, Pool Temperature, Washdown Transport, Sump Flow Rate, Pool Turbulence, Pool Velocity Injection Flow 1' Operating Trains, Containment Rate Accident Time Temperature, Pool Temperature, Sump Flow Rate, Pool Turbulence, Pool Velocity, Core Flow Rate Sump Flow Rate 1' Spray Flow Rate, Pool Turbulence, Pool Injection Flow Rate, Velocity, Strainer Operating Trains, Approach Velocity, Clean Accident Time Strainer Head Loss, NPSH Available, Vortex Air Ingestion, Degasification Page 24 of 260 South Texas Project Risk-Informed GSI-191 Evaluation Volume 3: CASA Grande Analysis RI-GSI191-V03 Revision 1 Table 2.1.2 -Input variables used primarily in debris generation analysis Design Input Conservative Preceding Direct-Input Proceeding Direct- Comments Variable Direction Variables Output Variables LOCA 1' N/A Break Location, Break Frequency Size Insulation N/A N/A Debris Quantity, Size Location Distribution, Blowdown Transport Qualified N/A N/A Debris Quantity, Coatings Blowdown Transport Location Unqualified
'1 N/A Debris Quantity Coatings Quantity Unqualified N/A N/A Washdown Transport, Coatings Initial Debris Distribution Location Unqualified
' Accident Time Debris Quantity, Coatings Failure Washdown Transport, Recirculation Transport Latent Debris '1' N/A Debris Quantity Quantity Miscellaneous
'1' N/A Debris Quantity Debris Quantity Destruction N/A ZOI Size Pressure ZOI Size '" Break Size, Destruction Debris Quantity If breaks on secondary Pressure, RCS Pressure, side could lead to RCS Temperature recirculation, the secondary side pressure and temperature are also preceding inputs.Debris Size Break Location, Blowdown Transport, Distribution Insulation Location Washdown Transport, Pool Fill Transport, Initial Debris Distribution, Settling Velocity, Tumbling Velocity, Recirculation Transport, Debris Erosion, Strainer Head Loss, Debris Penetration, Incore Head Loss Debris Density N/A Settling Velocity, Strainer Lower density increases Head Loss, Incore Head transport, higher Loss density increases head loss Page 25 of 260 South Texas Project Risk-Informed GSI-191 Evaluation Volume 3: CASA Grande Analysis RI-GS1191-V03 Revision 1 Design Input Conservative Preceding Direct-Input Proceeding Direct- Comments Variable Direction Variables Output Variables Debris Quantity T" Break Location, Precipitant Insulation Location, Concentrations, Strainer Qualified Coatings Bed Thickness, Strainer Location, ZOI Size, Approach Velocity, Debris Unqualified Coatings Penetration Failure, Latent Debris Quantity, Miscellaneous Debris Quantity Debris Generation Analysis I CASA Grande Inputs I I CASA Grande Calculations f(t) = function of accident time Figure 2.1.1 -Illustration of input variable relationships for debris generation analysis Page 26 of 260 South Texas Project Risk-Informed GSI-191 Evaluation Volume 3: CASA Grande Analysis RI-GSI191-V03 Revision 1 Table 2.1.3 -Input variables used primarily in chemical effects analysis Design Input Conservative Preceding Direct-Input Proceeding Direct- Comments Variable Direction Variables Output Variables RWST N/A Initial Pool Chemistry Concentration of Chemistry Boron, Silica, etc.Fuel Cycle Time N/A N/A RCS Chemistry RCS Chemistry Fuel Cycle Time Initial Pool Chemistry Concentration of Boron, Lithium, etc.Accumulator N/A Initial Pool Chemistry Concentration of Chemistry Boron, Silica, etc.Buffer Quantity N/A Initial Pool Chemistry Initial Pool RWST Injection Pool pH, Chemical Chemistry Volume, RWST Precipitant Concentration Chemistry, RCS Volume, RCS Chemistry, Accumulator Injection Volume, Accumulator Chemistry, Buffer Quantity Cable Quantity '1 N/A Acid Formation Radiological 1' N/A Acid Formation Dose Acid Formation
'1 Cable Quantity, Pool pH Long-term reductions in Radiological Dose, pH due to acid Accident Time formation will tend to reduce the solubility limits for precipitates.
Pool pH t'J Initial Pool Chemistry, Material Release Rates, Acid Formation, Solubility Limits Accident Time Metal Quantity 1' N/A Material Release Rates Material 1' Debris Quantity, Metal Precipitant Release Rates Quantity, Pool pH, Pool Concentrations Temperature, Active Pool Volume Precipitant
-" Active Water Volume, Precipitate Form, Concentrations Material Release Rates, Precipitate Quantity Accident Time Solubility Limits ' Pool pH, Pool Precipitate Form, Temperature Precipitate Quantity Precipitate N/A Precipitant Strainer Head Loss, Amorphous precipitates Form Concentrations, Incore Head Loss generally cause higher Solubility Limits, head losses than Accident Time crystalline precipitates Precipitate
'" Precipitant Strainer Head Loss, Quantity Concentrations, Incore Head Loss Solubility Limits, Accident Time Page 27 of 260 South Texas Project Risk-Informed GSI-191 Evaluation Volume 3: CASA Grande Analysis RI-GS1191-V03 Revision 1 Chemical Effects Analysis RWST Injection Volume/Chemistry, RCS Volume/Chemistry, Accumulator Injection Volume/Chemistry, Buffer Quantity CASA Grande Inputs CASA Grande Calculations I-it) = function of accident time Radiological Dose, Cable Quantity Initial Pool Chemistry Acid Formationf(Pool pH/:(-t L- I... -.. I (t)t)Pool Temperaturef (t)ubility Limitsf(t), i DI Debris Quantityf(t)
--Sol ,Metal Quantityj tive Water Volume : Material Release Rates f(t)_l I,----- ---------Ac I..------------------
I, Precipitate OQuantity/(t), Precipitant Concentrations f (t)L, F , Precipitate Form f(t)Figure 2.1.2 -Illustration of input variable relationships for chemical effects analysis Table 2.1.4 -Input variables used primarily in debris transport analysis Design Input Conservative Preceding Direct-Input Proceeding Direct- Comments Variable Direction Variables Output Variables Grating N/A N/A Blowdown Transport, Location Washdown Transport Blowdown Break Location, Initial Debris Distribution, Transport Insulation Location, Strainer Transport Qualified Coatings Location, Grating Location, Debris Size Distribution Page 28 of 260 South Texas Project Risk-Informed GSI-191 Evaluation Volume 3: CASA Grande Analysis RI-GSI191-V03 Revision 1 Design Input Conservative Preceding Direct-Input Proceeding Direct- Comments Variable Direction Variables Output Variables Washdown '1 Spray Flow Rate, Initial Debris Distribution, Transport Unqualified Coatings Strainer Transport Location, Unqualified Coatings Failure, Debris Size Distribution, Grating Location, Accident Time Pool Fill ', Inactive Cavity Volume, Initial Debris Distribution, Transport Debris Size Distribution Strainer Transport Settling Velocity Pool Temperature, Recirculation Transport Debris Size Distribution, Debris Density Tumbling '1 Debris Size Distribution Recirculation Transport, Velocity Debris Erosion Pool Turbulence
'" Spray Flow Rate, Recirculation Transport, Injection Flow Rate, Debris Erosion Sump Flow Rate, Pool Water Level Pool Velocity 1" Spray Flow Rate, Recirculation Transport Injection Flow Rate, Sump Flow Rate, Pool Water Level Initial Debris N/A Unqualified Coatings Recirculation Transport Distribution Location, Debris Size Distribution, Blowdown Transport, Washdown Transport, Pool Fill Transport Recirculation 1" Break Location, Strainer Transport Transport Operating Trains, Unqualified Coatings Failure, Settling Velocity, Tumbling Velocity, Pool Turbulence, Pool Velocity, Initial Debris Distribution, Accident Time Debris Erosion '" Debris Size Distribution, Strainer Transport Pool Turbulence, Pool Velocity, Accident Time Strainer '1 Blowdown Transport, Strainer Head Loss, Debris Transport Washdown Transport, Penetration Pool Fill Transport, Recirculation Transport, Debris Erosion, Accident Time Page 29 of 260 South Texas Project Risk-Informed GSI-191 Evaluation Volume 3: CASA Grande Analysis RI-GSI191-V03 Revision 1 Debris Transport Analysis (Part 1)CASA Grande Inputs CASA Grande Calculations f(t) = function of accident time Grating Location Figure 2.1.3 -Illustration of input variable relationships for debris transport analysis (Part 1)Page 30 of 260 South Texas Project Risk-Informed GSI-191 Evaluation Volume 3: CASA Grande Analysis RI-GS1191-V03 Revision 1 Debris Transport Analysis (Part 2)CASA Grande Inputs]I CASA Grande Calculations I_/'(t) = function of accident time-Blowdown Transport Unqualified Coatings Location I! l IDbisSz Debris Size Distribution-
-- WashdownTransport_ (t) I-Initial Debris Distribution Pool Temperaturef(t), Debris Density I __-tPool Fill Transport-b4 C I Break Location Operating Pumps f(t)L- Recirculation
-.F Settling Velocity Tumbling Velocity Pool Turbulencef(t), , Spray Flow Ratef(t), Pool Velocityf (t) T. Injection Flow Rate f(_ _ ,_ I lSump Flow Rate f(t), Transportf(t)
I.1 / Pool Water Level t),!Figure 2.1.4 -Illustration of input variable relationships for debris transport analysis (Part 2)Table 2.1.5 -Input variables used primarily in strainer head loss analysis Design Input Conservative Preceding Direct-Input Proceeding Direct- Comments Variable Direction Variables Output Variables Strainer Height '" N/A NPSH Available, Degasification Strainer Area '1, N/A Debris Bed Thickness, Strainer Approach Velocity, Debris Penetration Strainer 4 N/A Debris Bed Thickness, Interstitial Strainer Approach Volume Velocity Debris Bed '1 4 Strainer Area, Strainer Strainer Head Loss, Debris Thickness Interstitial Volume, Penetration Debris Quantity, Strainer Transport, Operating Trains, Accident Time Page 31 of 260 South Texas Project Risk-Informed GSI-191 Evaluation Volume 3: CASA Grande Analysis RI-GS1291-V03 Revision 1 Design Input Conservative Preceding Direct-Input Proceeding Direct- Comments Variable Direction Variables Output Variables Strainer '1 Sump Flow Rate, Strainer Head Loss, Approach Strainer Area, Strainer Vortex Air Ingestion, Velocity Interstitial Volume, Debris Penetration Debris Quantity, Strainer Transport, Operating Trains, Accident Time Clean Strainer '1 Pool Temperature, Strainer Head Loss Head Loss Sump Flow Strainer Head '" Pool Temperature, Degasification, Sump Loss Strainer Approach Failure Velocity, Clean Strainer Head Loss, Debris Bed Thickness, Debris Size Distribution, Debris Density, Precipitate Form, Precipitate Quantity, Accident Time NPSH Required I' Gas Void Fraction, NPSH Margin Accident Time NPSH Available , Strainer Height, Pool NPSH Margin Water Level, Containment Pressure, Pool Temperature, Sump Flow Rate, Accident Time NPSH Margin 1 NPSH Required, NPSH Sump Failure Acceptance criterion Available, Accident compared against Time strainer head loss Structural 4, N/A Sump Failure Acceptance criterion Margin compared against strainer head loss Page 32 of 260 South Texas Project Risk-Informed GSI-191 Evaluation Volume 3: CASA Grande Analysis RI-GS1191-V03 Revision 1 Strainer Head Loss Analysis I CASA Grande Inputs]CASA Grande Calculations Strainer Area, Strainer Interstit_f(t) = function of accident time I Debris Quantityf(t), tial Volume Strainer Transport_[(t), Operating Trainsf(t)
)4 1 Debris Bed Thicknessf(t)
Debris Size Distribution, Debris Density, Precipitate Quantityf(t), Precipitate Form i(t)------------I SPool Temperaturef (t)I Pool Water Level, Strainer Height, Containment Pressuref(t)
Figure 2.1.5 -Illustration of input variable relationships for strainer head loss analysis Table 2.1.6 -Input variables used primarily in gas intrusion analysis Design Input Conservative Preceding Direct-Input Proceeding Direct- Comments Variable Direction Variables Output Variables Vortex Air ' Pool Water Level, Gas Void Fraction Ingestion Strainer Approach Velocity Degasification
'" Strainer Height, Pool Gas Void Fraction Water Level, Containment Pressure, Pool Temperature, Sump Flow Rate, Strainer Head Loss, Accident Time Gas Void "1" Vortex Air Ingestion, NPSH Required, Sump Fraction Degasification, Failure Accident Time Page 33 of 260 South Texas Project Risk-Informed GSI-191 Evaluation Volume 3: CASA Grande Analysis RI-GS1191-V03 Revision 1 Gas Intrusion Analysis CASA Grande Inputs I CASA Grande Calculations f(t) = function of accident time_ Sump Flow Ratef (t), Strainer Heigh uPo l Rate Le t)l Pool Temperat Pool Water Level Containment F Strainer Head Vortex Air Ingestion Degasificationf(t)
L _-it, uref(t), Pressuref(t), Lossf(t)I I Gas Void F ractionf(t)
I IPump Gas Limits I Sump Failuref (t)Figure 2.1.6 -Illustration of input variable relationships for gas intrusion analysis Table 2.1.7 -Input variables used primarily in debris penetration and in-vessel effects analysis Design Input Conservative Preceding Direct-Input Proceeding Direct- Comments Variable Direction Variables Output Variables Debris 1' Debris Size Distribution, Incore Head Loss Penetration Debris Quantity, Strainer Transport, Strainer Area, Debris Bed Thickness, Strainer Approach Velocity Page 34 of 260 South Texas Project Risk-Informed GSI-191 Evaluation Volume 3: CASA Grande Analysis RI-GSl191-V03 Revision 1 Design Input Conservative Preceding Direct-Input Proceeding Direct- Comments Variable Direction Variables Output Variables Heat Exchanger 1' Pool Temperature Reactor Inlet Temperature Temperature Drop Reactor Inlet , Pool Temperature, Incore Head Loss, Boil-off Temperature Heat Exchanger Rate Temperature Drop Core Flow Rate '1' Injection Flow Rate, Incore Head Loss, Boron Break Location, Break Precipitation, In-Vessel Size, Driving Head, Failure Incore Head Loss, Accident Time Incore Head I" Debris Penetration, Core Flow Rate Loss Debris Size Distribution, Debris Density, Precipitate Form, Precipitate Quantity, Reactor Inlet Temperature, Core Flow Rate, Accident Time Driving Head Break Location, Break Core Flow Rate Size Boil-off Rate 1 RCS Pressure, Reactor Required Core Flow Rate Inlet Temperature, Reactor Power Required Core Accident Time, Boil-off Boron Precipitation, In- Acceptance criterion for Flow Rate Rate Vessel Failure flow required to remove decay heat and prevent boron precipitation compared to actual core flow rate Boron 1' Core Flow Rate, In-Vessel Failure Precipitation Required Core Flow Rate, Accident Time Page 35 of 260 South Texas Project Risk-informed GSI-191 Evaluation Volume 3: CASA Grande Analysis RI-GS1191-V03 Revision 1 Debris Penetration and Core Blockage Analysis CASA Grande Inputs]CASA Grande Calculations f(t) = function of accident time I Debris Size Distribution I-IPool Temperature 1(t)Heat Exchanger Temperature Drop f(t)Reactor Inlet Debris Density, Precipitate Quantityf(t), Precipitate Form f(t)---------- ---lDebris Quantity_/(t), Strainer Transport/ (t), Strainer Area, Debris Bed Thicknessf(t), Strainer Approach Velocityf(t)
I emperaturet
/ t) :I_---------------------
SBreak Location, I, Incore Head Lossf(t)-
- Required Core L"---- ------ Flow Rate ft Break Size------- ------' Core Flowl Ratei-(t)H Boo r.itation f(t)Driving Head _(t)Injection Flow Rate /(t) In-Vessel Failuref(t)
Figure 2.1.7 -Illustration of input variable relationships for debris penetration and core blockage analysis 2.2 Specific Inputs Used This section documents the specific design inputs used in the CASA Grande analysis.
An example input deck is provided in Appendix 1.2.2.1 Timing for Key Plant Response Actions There are a number of automated or proceduralized plant response actions that would occur following a LOCA event. The timing for these actions is important for the GSI-191 evaluation since the timing can have a significant impact on a variety of phenomena.
Immediately after a LOCA, several things would occur: 1) the accumulators would inject their inventory if the RCS pressure drops below approximately 600 psig (30), 2) the LHSI and HHSI pumps would start injecting water from the RWST into the cold legs, and 3) the CS pumps would start injecting water from the RWST into the containment spray headers if the containment pressure rises above 9.5 psig (31). Note that for breaks smaller than 2-inches, the Page 36 of 260 South Texas Project Risk-Informed GSI-191 Evaluation Volume 3: CASA Grande Analysis RI-GSI191-V03 Revision 1 accumulators would not inject, and the sprays would not be initiated since the RCS pressure would not drop below 600 psig before the accumulators are secured, and the containment pressure would not rise above 9.5 psig (5).Other important longer-term actions include:* Securing one CS pump if all three CS pumps are successfully initiated* Securing all CS pumps later in the event" Switchover to ECCS sump recirculation after the RWST has been drained* Switchover to hot leg injection Per procedure, if all three trains of containment spray are successfully initiated, one of the three pumps would be manually secured (32; 33). Since this is a continually monitored action that is intended to conserve the RWST, the third train of containment spray would be secured early in the event prior to switchover to recirculation.
In general, the remaining two trains of sprays would be on for a minimum of 6.5 hours5.787037e-5 days <br />0.00139 hours <br />8.267196e-6 weeks <br />1.9025e-6 months <br /> for medium and large breaks. The termination criteria are 1) at least 6.5 hours5.787037e-5 days <br />0.00139 hours <br />8.267196e-6 weeks <br />1.9025e-6 months <br /> has passed since the beginning of the event, 2) containment pressure has dropped below 6.5 psig, 3) the iodine levels in containment are not abnormally high, and 4) the Technical Support Center (TSC) staff has agreed that the sprays can be terminated (34). Typically, the pressure will drop below 6.5 psig in less than an hour (5), and the iodine levels would be relatively low given that there is no core damage early in the LOCA event. According to the STP operators (35), the decision to terminate containment sprays would probably be made as soon as the pressure drops below 6.5 psig (well before reaching 6.5 hours5.787037e-5 days <br />0.00139 hours <br />8.267196e-6 weeks <br />1.9025e-6 months <br />). Therefore, the best-estimate time for securing containment sprays is at 6.5 hours5.787037e-5 days <br />0.00139 hours <br />8.267196e-6 weeks <br />1.9025e-6 months <br />.The timing for switchover to recirculation is dependent on the volume of water in the RWST and the total ECCS and CSS flow rate. Table 2.2.1 shows the sump switchover timing as a function of break size 2 (5).2 This is based on best-estimate conditions where all pumps are available.
However, these results can be conservatively applied to scenarios where some pumps fail to start since a reduction in the overall ECCS and CSS flow rates would delay sump switchover, thereby delaying strainer head loss and core blockage as the pump NPSH margin increases and the required core flow rate decreases.
Page 37 of 260 South Texas Project Risk-Informed GSI-191 Evaluation Volume 3: CASA Grande Analysis RI-GSI191-V03 Revision 1 Table 2.2.1 -Sump switchover time Break Size Sump Switchover Sump Switchover (in) Time (s) Time (min)1.5" 20,239 337 2" 4,750 79 4" 3,353 56 6" 2,653 44 8" 2,268 38 12" 1,873 31 27.5" DEGB 1,773 30 Switchover to hot leg injection is started 5.5 hours5.787037e-5 days <br />0.00139 hours <br />8.267196e-6 weeks <br />1.9025e-6 months <br /> after the beginning of the event (32; 36). As discussed in Assumption L.i, the switchover steps are assumed to be completed 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> after the beginning of the event.2.2.2 Containment Geometry Containment geometry data includes potential break locations (i.e. pipe welds), insulation quantities and locations, robust barrier locations, etc. This information is included in the STP containment computer aided drafting (CAD) model, which has been formally prepared, reviewed, and approved for use in safety-related applications (4).Additional description of the CAD model is provided in Section 5.2.2.2.3 LOCA Frequencies The LOCA frequency input for CASA Grande is taken from two sources-an overall frequency for different break sizes and relative frequencies at various locations based on specific degradation mechanisms (DMs). The overall frequency for different break sizes is based on the values provided in NUREG-1829 (37), which were fit using a bounded Johnson distribution as shown in Table 2.2.2 (8).Page 38 of 260 South Texas Project Risk-Informed GSI-191 Evaluation Volume 3: CASA Grande Analysis RI-GSI191-V03 Revision 1 Table 2.2.2 -NUREG-1829 PWR current-day LOCA frequencies and fitted Johnson parameters Size NUREG-1829 Quantiles Fitted Johnson Parameters (in) 5th Median Mean 95_th 6 k A 0.5 6.80E-05 6.30E-04 1.90E-03 7.10E-03 1.650950 5.256964E-01 4.117000E-05 1.420E-02 1.625 5.00E-06 8.90E-05 4.20E-04 1.60E-03 1.646304 4.593913E-01 2.530000E-06 3.200E-03 2i 3.69E-06 6.57E-05 3.10E-04 1.18E-03 1.646308 4.593851E-01 1.870000E-06 2.361E-03 3 2.10E-07 3.40E-06 1.60E-05 6.10E-05 1.646605 4.589467E-01 1.200000E-07 1.220E-04 6_ 6.30E-08 1.08E-06 5.20E-06 1.98E-05 1.646403 4.566256E-01 3.000000E-08 3.965E-05 7 1.40E-08 3.10E-07 1.60E-06 6.10E-06 1.645739 4.487957E-01 6.023625E-09 1.220E-05 14 4.10E-10 1.20E-08 2.OOE-07 5.80E-07 1.645211 3.587840E-01 2.892430E-10 1.160E-06 31 3.50E-11 1.20E-09 2.90E-08 8.10E-08 1.645072 3.343493E-01 2.636770E-11 1.600E-07 The relative frequencies of breaks in various weld locations are based on specific DMs for categories of welds as shown in through Table 2.2.6 (7). There are a total of 45 different categories that are considered.
Additional details on the LOCA Frequencies are provided in Section 5.3.3 The quantiles are not explicitly defined in NUREG-1829 for 2-inch and 6-inch breaks. However, these values were linearly interpolated from the 1-5/8-inch, 3-inch, and 7-inch break categories (24).Page 39 of 260 South Texas Project Risk-Informed GSI-191 Evaluation Volume 3: CASA Grande Analysis RI-GSI191-V03 Revision 1 Table 2.2.3 -Relative frequencies vs. break size for hot leg, SG inlet, cold leg, and surge line welds (Categories 1A through 4D)Category 1A 1B ic 2 3A 3B 3C 3D 4A 4B 4C 4D System Hot Leg Hot Leg Hot Leg SG Inlet Cold Leg Cold Leg Cold Leg Cold Leg Surge Line Surge Line Surge Line Surge Line Pipe Size (in) 29 29 29 29 27.5 31 27.5 31 16 16 16 2.5 DEGB (in) 41.01 41.01 41.01 41.01 38.89 43.84 38.89 43.84 22.63 22.63 22.63 3.54 Weld Type B-F B-J B-J B-F B-F B-F B-J B-J B-F B-J BC B-J DM SC, D&C D&C TF, D&C SC, D&C SC, D&C SC, D&C D&C D&C SC, TF, D&C TF, D&C TF, D&C TF, D&C No. Welds 4 11 1 4 4 4 12 24 1 7 2 6 Break Size, X F(LOCA>X)
F(LOCA>X)
F(LOCAX) F(LOCA>X)
F(LOCAX) F(LOCA>X)
F(LOCA>X)
F(LOCAX) F(LOCAX) F(LOCAX) F(LOCAX) F(LOCAX)(in)0.50 4.02E-07 1.95E-09 1.25E-08 1.98E-06 1.51E-07 1.51E-07 2.79E-09 2.79E-09 9.75E-06 7.44E-08 1.21E-07 7.44E-08 0.75 1.00 1.40 1.50 9.25E-08 4.49E-10 2.87E-09 4.59E-07 3.43E-08 3.43E-08 6.33E-10 6.33E-10 3.30E-06 2.52E-08 4.11E-08 2.52E-08 1.99 2.00 6.92E-08 3.36E-10 2.15E-09 3.45E-07 2.38E-08 2.38E-08 4.39E-10 4.39E-10 2.43E-06 1.85E-08 3.02E-08 1.85E-08 2.80 2.83 3.00 4.61E-08 2.24E-10 1.43E-09 2.31E-07 1.42E-08 1.42E-08 2.62E-10 2.62E-10 1.581-06 1.20E-08 1.97E-08 1.20E-08 3.54 9.42E-09 4.00 3.19E-08 1.55E-10 9.90E-10 1.60E-07 9.49E-09 9.49E-09 1.75E-10 1.75E-10 1.03E-06 7.82E-09 1.28E-08 4.24 5.66 6.00 1.89E-08 9.19E-11 5.89E-10 9.52E-08 5.39E-09 5.39E-09 9.95E-11 9.95E-11 5.58E-07 4.26E-09 6.94E-09 6.75 1.61E-08 7.83E-11 5.01E-10 8.12E-08 4.53E-09 4.53E-09 8.36E-11 8.36E-11 4.68E-07 3.57E-09 5.82E-09 6.80 7.20 8.49 10.00 11.31 14.00 7.01E-09 3.40E-11 2.18E-10 3.35E-08 2.01E-09 2.01E-09 3.70E-11 3.70E-11 1.181-07 9.03E-10 1.47E-09 14.14 16.00 9.19E-08 7.02E-10 1.15E-09 16.97 20.00 3.70E-09 1.80E-11 1.15E-10 1.81E-08 1.15E-09 1.15E-09 2.11E-11 2.11E-11 6.14E-08 4.69E-10 7.65E-10 22.63 4.77E-08 3.64E-10 5.931-10 27.50 6.96E-10 6.96E-10 1.281-11 1.281-11 29.00 1.90E-09 9.24E-12 5.92E-11 9.571-09 31.50 1.64E-09 7.97E-12 5.11E-11 8.30E-09 5.63E-10 5.63E-10 1.04E-11 1.04E-11 38.89 4.12E-10 7.60E-12 41.01 1.04E-09 5.03E-12 3.22E-11 5.24E-09 43.80 1 1 1 1 3.38E-10 6.23E-12 I Page 40 of 260 South Texas Project Risk-Informed GSI-191 Evaluation Volume 3: CASA Grande Analysis RI-GS1191-V03 Revision 1 Table 2.2.4 -Relative frequencies vs. break size for pressurizer and small bore line welds (Categories 5A through 6B)Category SA 5B 5C 5D 5E 5F 5G 5H 51 SJ 6A 6B System Pressurizer Pressurizer Pressurizer Pressurizer Pressurizer Pressurizer Pressurizer Pressurizer Pressurizer Pressurizer Small Bore Small Bore Pipe Size (in) 6 3 4 3 6 6 6 6 4 2 2 1 DEGB (in) 8.49 4.24 5.66 4.24 8.49 8.49 8.49 8.49 5.66 2.83 2.83 1.41 Weld Type B-J B-J B-J B-J B-J B-F B-F B-F BC B-J B-J B-J DM TF, D&C TF, D&C D&C D&C D&C SC, TF, D&C SC, D&C D&C (Weld D&C TF, D&C VF, SC, D&C VF, SC, D&C Overlay)No. Welds 29 14 53 4 29 0 0 4 2 2 16 193 Break Size, X F(LOCA>X)
F(LOCA>X)
F(LOCA>X)
F(LOCA>X)
F(LOCA>X)
F(LOCA>X)
F(LOCA>X)
F(LOCA>X)
F(LOCA>X)
F(LOCA>X)
F(LOCA>X)
F(LOCA>X)(in)______
0.50 4.59E-08 4.59E-08 1.72E-08 1.72E-08 1.72E-08 5.09E-06 5.01E-06 1.74E-08 1.72E-08 4.59E-08 1.22E-06 1.22E-06 0.75 2.76E-08 2.76E-08 1.03E-08 1.03E-08 1.03E-08 3.06E-06 3.01E-06 1.05E-08 1.03E-08 2.76E-08 7.18E-07 7.18E-07 1.00 1.96E-08 1.96E-08 7.33E-09 7.33E-09 7.33E-09 2.17E-06 2.13E-06 7.42E-09 7.33E-09 1.96E-08 5.OOE-07 5.00E-07 1.40 3.30E-07 3.30E-07 1.50 1.24E-08 1.24E-08 4.64E-09 4.64E-09 4.64E-09 1.38E-06 1.35E-06 4.70E-09 4.64E-09 1.24E-08 3.08E-07 1.99 1.75E-07 2.00 6.64E-09 6.64E-09 2.49E-09 2.49E-09 2.49E-09 7.36E-07 7.24E-07 2.52E-09 2.49E-09 6.64E-09 1.73E-07 2.80 8.66E-08 2.83 3.13E-09 3.00 2.75E-09 2.75E-09 1.03E-09 1.03E-09 1.03E-09 3.05E-07 3.OOE-07 1.04E-09 1.03E-09 3.54 4.00 4.24 1.30E-09 1.30E-09 4.87E-10 4.87E-10 4.87E-10 1.44E-07 1.42E-07 4.94E-10 4.87E-10 5.66 6.26E-10 2.34E-10 2.34E-10 6.94E-08 6.83E-08 2.37E-10 2.34E-10 6.00 5.47E-10 2.05E-10 6.06E-08 5.96E-08 2.07E-10 6.75 4.16E-10 1.56E-10 4.61E-08 4.54E-08 1.58E-10 6.80 7.20 8.49 2.64E-10 9.89E-11 2.93E-08 2.88E-08 1.ODE-10 10.00 11.31 14.00 14.14 16.00 16.97 20.00 22.63 27.50 29.00 31.50 38.89 41.01 43.80 Page 41 of 260 South Texas Project Risk-Informed GSI-191 Evaluation Volume 3: CASA Grande Analysis RI-GSI191-V03 Revision 1 Table 2.2.5 -Relative frequencies vs. break size for safety injection and recirculation line welds (Categories 7A through 7L)Category 7A 78 7C 7D 7E 7F 7G 7H 71 71 7K 7L System SIR SIR SIR SIR SIR SIR SIR SIR SIR SIR SIR SIR Pipe Size (in) 12 8 8 12 12 10 8 6 4 3 2 1.5 DEGB (in) 16.97 11.31 11.31 16.97 16.97 14.14 11.31 8.49 5.66 4.24 2.83 2.12 Weld Type B-J B-A B-A B-A BC, B-i B-A BC, B-i B-i BC BC BC B-A DM TF, D&C TF, D&C SC, TF, D&C 5C, D&C D&C D&C D&C D&C D&C D&C D&C D&C No. Welds 21 9 3 3 57 30 42 23 5 9 10 0 Break Size X F(LOCA>X)
F(LOCA>X)
F(LOCA>X)
F(LOCA>X)
F(LOCA>X)
F(LOCA>X)
F(LOCA>X)
F(LOCA>X)
F(LOCA>X)
F(LOCA>X)
F(LOCA>X)
F(LOCA>X)(in)______
0.50 2.78E-06 2.78E-06 3.10E-06 3.54E-07 1.14E-08 1.14E-08 1.14E-08 1.14E-08 1.14E-08 1.14E-08 1.14E-08 1.14E-08 0.75 1.67E-06 1.67E-06 1.86E-06 2.12E-07 6.84E-09 6.84E-09 6.84E-09 6.84E-09 6.84E-09 6.84E-09 6.84E-09 6.84E-09 1.00 1.18E-06 1.18E-06 1.32E-06 1.51E-07 4.85E-09 4.85E-09 4.85E-09 4.85E-09 4.85E-09 4.85E-09 4.85E-09 4.85E-09 1.40 1.50 7.48E-07 7.48E-07 8.34E-07 9.54E-08 3.07E-09 3.07E-09 3.07E-09 3.07E-09 3.07E-09 3.07E-09 3.07E-09 3.07E-09 1.99 2.00 4.01E-07 4.01E-07 4.48E-07 5.12E-08 1.65E-09 1.65E-09 1.65E-09 1.65E-09 1.65E-09 1.65E-09 1.65E-09 1.651-09 2.80 2.83 1.67E-07 1.67E-07 1.86E-07 2.13E-08 6.85E-10 6.85E-10 6.85E-10 6.85E-10 6.85E-10 6.85E-10 6.85E-10 3.00 3.54 4.00 8.50E-08 8.50E-08 9.48E-08 1.08E-08 3.49E-10 3.49E-10 3.49E-10 3.49E-10 3.49E-10 3.49E-10 4.24 7.41E-08 7.41E-08 8.26E-08 9.45E-09 3.04E-10 3.04E-10 3.04E-10 3.04E-10 3.04E-10 3.04E-10 5.66 3.79E-08 3.79E-08 4.23E-08 4.84E-09 1.56E-10 1.56E-10 1.56E-10 1.56E-10 1.56E-10 6.00 3.31E-08 3.31E-08 3.70E-08 4.23E-09 1.36E-10 1.36E-10 1.36E-10 1.36E-10 6.75 2.52E-08 2.52E-08 2.81E-08 3.22E-09 1.04E-10 1.04E-10 1.04E-10 1.04E-10 6.80 7.20 2.22E-08 2.22E-08 2.48E-08 2.83E-09 9.12E-11 9.12E-11 9.12E-11 9.12E-11 8.49 1.60E-08 1.60E-08 1.79E-08 2.04E-09 6.58E-11 6.58E-11 6.58E-11 6.58E-11 10.00 1.16E-08 1.16E-08 1.29E-08 1.47E-09 4.75E-11 4.75E-11 4.75E-11 11.31 9.11E-09 9.11E-09 1.02E-08 1.16E-09 3.74E-11 3.74E-11 3.74E-11 14.00 14.14 5.93E-09 7.56E-10 2.44E-11 2.44E-11 16.00 16.97 4.05E-09 5.16E-10 1.66E-11 20.00 22.63 27.50 29.00 31.50 38.89 41.01 43.80 Page 42 of 260 South Texas Project Risk-Informed GSI-191 Evaluation Volume 3: CASA Grande Analysis RI-GSI191-V03 Revision 1 Table 2.2.6 -Relative frequencies vs. break size for accumulator injection and CVCS line welds (Categories 7M through 8F)Category 7M 7N 70 8A 8B 8C 8D 8E 8F System ACC ACC ACC cvcs cvcs cvcs cvcs cvcs cvcs Pipe Size (in) 12 12 12 2 4 2 4 4 4 DEGB (in) 16.97 16.97 16.97 2.83 5.66 2.83 5.66 5.66 5.66 Weld Type B-J B-J BC, B-J B-J B-J B-J B-J BC BC DM SC, D&C TF, D&C D&C TF, VF, D&C TF, VF, D&C VF, D&C VF, D&C TF, D&C D&C No. Welds 0 35 15 10 19 47 6 4 1 Break Size, X F(LOCA>X)
F(LOCAX) F(LOCA>X)
F(LOCA>X)
F(LOCA>X)
F(LOCA>X)
F(LOCA>X)
F(LOCA>X)
F(LOCA>X)(in)______
0.50 3.54E-07 5.18E-08 6.26E-09 4.28E-08 4.28E-08 1.87E-08 1.87E-08 7.98E-08 1.87E-08 0.75 2.12E-07 3.11E-08 3.75E-09 2.57E-08 2.57E-08 1.12E-08 1.12E-08 4.79E-08 1.12E-08 1.00 1.51E-07 2.21E-08 2.66E-09 1.82E-08 1.82E-08 7.97E-09 7.97E-09 3.40E-08 7.97E-09 1.40 1.50 9.54E-08 1.40E-08 1.69E-09 1.15E-08 1.15E-08 5.04E-09 5.04E-09 2.15E-08 5.04E-09 1.99 2.00 5.12E-08 7.49E-09 9.04E-10 6.03E-09 6.03E-09 2.64E-09 2.64E-09 1.12E-08 2.64E-09 2.80 2.83 2.13E-08 3.12E-09 3.76E-10 3.00 2.42E-09 2.42E-09 1.06E-09 1.06E-09 4.51E-09 1.06E-09 3.54 4.00 1.08E-08 1.67E-09 2.02E-10 1.26E-09 5.49E-10 2.34E-09 5.49E-10 4.24 9.45E-09 5.66 4.84E-09 7.09E-10 8.55E-11 5.77E-10 2.52E-10 1.08E-09 2.52E-10 6.00 4.23E-09 6.19E-10 7.47E-11 6.75 3.22E-09 6.80 4.71E-10 5.69E-11 7.20 2.83E-09 4.14E-10 5.00E-11 8.49 2.04E-09 10.00 1.47E-09 2.16E-10 2.61E-11 11.31 1.16E-09 14.00 14.14 7.56E-10 1.11E-10 1.34E-11 16.00 16.97 5.16E-10 7.56E-11 9.12E-12 20.00 22.63 27.50 29.00 31.50 38.89 41.01 43.80 Page 43 of 260 South Texas Project Risk-Informed GSI-191 Evaluation Volume 3: CASA Grande Analysis RI-GSI191-V03 Revision 1 2.2.4 Pump State Frequencies The frequency of various pump state combinations was determined based on the STP PRA model as shown in Table 2.2.7 (38). Note that these frequencies are based on the PRA without considering failure related to GSI-191 phenomena.
Only sequences ending in success, as opposed to core damage, are included in the pump combination state frequencies since only those sequences are candidates to transition to core damage when GSI-191 failure phenomena are considered.
Table 2.2.7 -Frequency of success pump combination states Working Working Working Pump State Case HHSI Pumps LHSI Pumps CS Pumps Frequency (year')1 3 3 3 2.64E-04 2 3 3 2 3.32E-06 3 3 3 1 7.53E-08 4 3 3 0 9.77E-09 5 3 2 3 3.49E-06 6 3 2 2 4.38E-08 7 3 2 1 9.80E-10 8 3 2 0 1.25E-10 9 3 1 3 3.22E-08 10 3 1 2 3.95E-10 11 3 1 1 7.59E-12 12 3 1 0 9.85E-13 13 3 0 3 <1E-14 14 3 0 2 <1E-14 15 3 0 1 <1E-14 16 3 0 0 <1E-14 17 2 3 3 1.94E-06 18 2 3 2 2.44E-08 19 2 3 1 5.39E-10 20 2 3 0 6.95E-11 21 2 2 3 1.17E-07 22 2 2 2 9.16E-06 23 2 2 1 7.81E-08 24 2 2 0 1.19E-09 25 2 1 3 7.65E-10 26 2 1 2 6.03E-08 27 2 1 1 4.93E-10 28 2 1 0 6.16E-12 Page 44 of 260 South Texas Project Risk-Informed GSI-191 Evaluation Volume 3: CASA Grande Analysis RI-GS1191-V03 Revision 1 Case Working Working Working Pump State HHSI Pumps LHSI Pumps CS Pumps (year.u)29 2 0 3 <1E-14 30 2 0 2 <1E-14 31 2 0 1 <1E-14 32 2 0 0 <1E-14 33 1 3 3 2.67E-08 34 1 3 2 3.26E-10 35 1 3 1 6.18E-12 36 1 3 0 8.02E-13 37 1 2 3 6.43E-10 38 1 2 2 3.54E-08 39 1 2 1 2.84E-10 40 1 2 0 3.01E-12 41 1 1 3 9.96E-12 42 1 1 2 1.63E-09 43 1 1 1 4.34E-08 44 1 1 0 1.76E-10 45 1 0 3 <1E-14 46 1 0 2 <1E-14 47 1 0 1 *<1E-14 48 1 0 0 <1E-14 49 0 3 3 5.84E-11 50 0 3 2 6.24E-13 51 0 3 1 <1E-14 52 0 3 0 <1E-14 53 0 2 3 4.92E-13 54 0 2 2 3.50E-11 55 0 2 1 <1E-14 56 0 2 0 <1E-14 57 0 1 3 <1E-14 58 0 1 2 <1E-14 59 0 1 1 3.89E-11 60 0 1 0 <1E-14 61 0 0 3 <1E-14 62 0 0 2 <1E-14 63 0 0 1 <1E-14 64 0 0 0 <1E-14 Page 45 of 260 South Texas Project Risk-Informed GSI-191 Evaluation Volume 3: CASA Grande Analysis RI-GSI191-V03 Revision 1 2.2.5 Active Water Volume The active water volume is the total volume of water in containment (from the RWST, RCS, and accumulators) minus any water sequestered in inactive regions where there would be no significant mixing. The probability distribution for the mass of water injected from the RWST, RCS, and accumulators at STP was calculated based on the level alarms, technical specifications, operating history, etc. (14). The inactive regions in containment at STP are very small compared to the total volume of water. Therefore, the active volume is essentially the same as the total volume (14).The volume of water is temperature dependent and can be calculated using the following equation: Mactive 1'active -- Equation 1 P pool where: Vactive = Active water volume Mactive = Active water mass Ppooi = Density of pool as a function of the pool temperature Although the temperature of the water circulating through the ECCS and RCS will vary, it is reasonable to use the average pool temperature to determine the density for the active water volume since the majority of the water is in the pool.The active water mass can be calculated using Equation 2.Mactive = MRWST + MRCS + MAcc Equation 2 where: MRWST = Mass of water injected from the RWST MRCS = Mass of water in the RCS at the time of the accident MAce = Mass of water injected from the accumulators Table 2.2.8 and Figure 2.2.1 show the probability distribution for the mass of water injected from the RWST (14).Page 46 of 260 South Texas Project Risk-Informed GSI-191 Evaluation Volume 3: CASA Grande Analysis RI-GSI191-V03 Revision 1 Table 2.2.8 -RWST injection mass probability distribution inputs RWST Mass Input Function a 3,295,730 Ibm b 3,573,201 Ibm c 3,676,606 Ibm d 4,119,866 Ibm h 2.156E-06 0.0000025 0.000002 r 0.0000015 0.0.000001 0.0000005 0 3295730 Mass (Ibm) 4119866 Figure 2.2.1 -RWST injection mass probability distribution The mass of water in the RCS ranges from 591,395 Ibm to 623,532 Ibm (14). The mass of water injected from the accumulators ranges from 225,140 Ibm to 234,773 Ibm (14). Note that the accumulators only inject for medium or large breaks (14), so this mass should not be included for small breaks. Since the range between the minimum and maximum RCS and accumulator volumes is relatively small compared to the RWST injection volume, it is reasonable to assume a uniform probability distribution for the RCS and accumulator masses.Note that within this version of the analysis, the active water volume model was not implemented in CASA. See additional discussion at the end of Section 2.2.6.2.2.6 Pool Water Level The pool water level is based on the active water volume minus the transitory water volume (e.g. water circulating through the ECCS and CSS piping, containment sprays falling through the air or migrating Page 47 of 260 South Texas Project Risk-Informed GSI-191 Evaluation Volume 3: CASA Grande Analysis RI-GSI191-V03 Revision 1 down to the pool, condensation on walls and other surfaces, water still in the RCS, etc.). The pool water level can be calculated using the following equation: SVPO°L Equation 3 where: HP 0 0 1 = Height above the containment floor at Elevation
-11'3" Vpoo1 = Pool volume Apool = Pool area The area of the pool at STP is 12,301 ft 2 (14). The volume of the pool can be calculated using Equation 4.Vp 0 oo = Vactive -Vsub -Vlapor -VRCSrecirc
-Vtransitl
-Vtransit2
-Vcont 1 + Vcott2 Equation 4 where: VSub= Volume of cavities below the containment floor at Elevation
-11'3" Vvapor = Equivalent liquid volume of water vapor in the containment atmosphere VRCS,recirc
= Volume of water in the RCS during recirculation Vtransiti
= Volume of spray flow falling through the containment atmosphere Vtra.sit2
= Volume of break flow falling to the pool Vcontl = Volume of water held up in miscellaneous locations in containment Vcont2 = Volume of water that would move back to the pool after sprays are secured The active pool volume (Vactive) is calculated as shown in Section 2.2.5. The volume of cavities below the containment floor elevation (Vsub) is 1,478 ft 3 (14).The mass of water vapor in the atmosphere varies depending on the break size. It was calculated to be 178,944 Ibm for a small break LOCA (SBLOCA), 188,909 Ibm for a medium break LOCA (MBLOCA), and 198,873 Ibm for a large break LOCA (LBLOCA) (14). These values can be converted to the equivalent water volume (Vvapor) by dividing by the pool density (Ppooi).The volume of water in the RCS during recirculation (VRCS,recirc) is dependent on the break size and elevation (Ebreak) as shown in Table 2.2.9 (14). Elevation 32'-3" is the centerline of the hot and cold leg piping and Elevation 46'-9.5" is the top of the pressurizer surge line (14).Page 48 of 260 South Texas Project Risk-Informed GSI-191 Evaluation Volume 3: CASA Grande Analysis RI-GSI191-V03 Revision 1 Table 2.2.9 -Volume of water in the RCS during recirculation Break Size Break Elevation (Ebreak) RCS Volume (VRCSrecirc)
Ebreak -El 32.25' 2,940 ft 3 El 32.25' < Ebreak _< El 46.79' 9,1314 ft 3 MBLOCA______ Ebreak > El 46.79' 14,975 ft 3 SBLOCA Ebreak !5 El 46.79' 14,044 ft 3 Ebreak > El 46.79' 14,975 ft 3 The volume of spray water falling through the containment atmosphere can be calculated using the following equation (14): VtraatsitI
= 9S QCS Equation 5 where: Ocs = Containment spray flow rate in ft 3/s The volume of water spilling from the break to the pool can be calculated using Equation 6.Vtrnsi2 QS -2. [Ebl,,k -- (--11.25ft)]
s2El " 32.2ft/s 2 where: Equation 6 Os, = Total Sl flow rate in ft 3/s Ebreak = Break elevation in feet with respect to containment floor elevation at -11'3" There are a variety of locations where water may be held up in containment, and the volume of miscellaneous hold-up is significantly larger if containment sprays are activated.
The total volume of miscellaneous hold-up in containment (VMonti) is 495 ft 3 if sprays are never initiated and 7,817 ft 3 if sprays are initiated (14).The volume of water that would return to the pool after sprays are secured (Vcont 2) is 3,719' ft 3 (14).During the period when sprays are in operation or if they were never initiated, Vcont 2 would be 0 ft 3.4 This value is a conservative simplification of the volume specified in the water volume calculation where the steam generators are assumed to be completely full of water (18).5 This value is a conservative simplification of the volume specified in the water volume calculation based on a reduction in the MBLOCA vapor quantity and a pool density of 62.4 Ibrm/ft 3 (18).Page 49 of 260 South Texas Project Risk-Informed GSI-191 Evaluation Volume 3: CASA Grande Analysis RI-GSI191-V03 Revision 1 Note that within this version of the analysis, the pool volume was not explicitly calculated for each scenario in CASA. Instead, the ranges of pool volumes shown in Table 2.2.10 were sampled for small, medium, and large breaks (14). This volume was subsequently used to calculate the water level using Equation 3.Table 2.2.10- Range of water volumes implemented in CASA Grande Minimum Maximum Volume Break Size Volume (ft 3) (ft 3)LBLOCA 45,201 69,263 MBLOCA 39,533 69,444 SBLOCA 43,464 61,993 2.2.7 Pool Temperature The pool temperature profiles were determined for different break sizes based on thermal-hydraulic modeling.
Figure 2.2.2 shows the temperature profiles based on nominal conditions for 1.5-inch, 2-inch, 4-inch, 6-inch, g-inch, and 15-inch partial breaks, and a 27.5-inch DEGB (5). The temperature profiles for breaks that are 6 inches and larger have a similar trends, and the larger breaks have a higher peak temperature early in the event and then drop down to a lower overall temperature later in the event.Page 50 of 260 South Texas Project Risk-Informed GSI-191 Evaluation Volume 3: CASA Grande Analysis RI-GSI191-V03 Revision 1 280-1.5@1 -211 411 260-6" -8" -15'240 220 DEGM_~200 E220 160. ..140 120 100 0 5000 10000 15000 20000 25000 30000 3500 4 Time [sI Io 040000 Figure 2.2.2 -Nominal containment pool temperature profiles An interpolation scheme was developed to determine an appropriate temperature profile as a function of break size (6). Since the trend in temperature profiles changes significantly between the 6-inch and 4-inch break sizes, all breaks smaller than 6 inches were assumed to have a profile identical to the 6-inch break (see Assumption 1.j). The first step for the interpolation was to fit a series of piecewise continuous polynomial functions for each temperature profile. The temperature profiles were partitioned into four slices denoted as t 1 , t 2 , t 3 , and t 4 , where t, = [0, 0.492 hr], t 2 = (0.492, 5.77 hr], t 3 = (5.77, 6.54 hr], and t 4= (6.54, 10 hr]. Since the temperature prior to the start of recirculation (1,772 s or 0.492 hr (5)) is not important for the GSI-191 evaluation, only the t 2 , t 3 , and t 4 data portions of the temperature curves were fit. A six-degree polynomial was used for each of the fits, which is defined by the following equation: Y = 00 + 0 1 X + 0 2 X 2+ 0 3 X 3+0 6X 4+ 6 5 X 5+0 X6 6 Equation 7 where: y = Temperature
(°F)x = Time (s)Page 51 of 260 South Texas Project Risk-Informed GSI-191 Evaluation Volume 3: CASA Grande Analysis RI-GSI191-V03 Revision 1 0 = Fitting parameters The coefficients for each of the temperature profiles and each time segment are shown in Table 2.2.12.Table 2.2.11 -Fitting results for nominal temperature profiles Coefficients Function Par.6" Break 8" Break 15" Break 27.5" Break 60 206.460 214.460 187.685 152.898 E) -0.024 -0.034 -0.001 0.031 02 5.4023E-06 9.4859E-06 1.2445E-07
-9.2927E-06 Ftio 03 -5.5721E-10
-1.3083E-09
-1.5989E-10 1.1288E-09 04 2.7794E-14 9.1334E-14 2.1284E-14
-6.9472E-14 05 -6.3980E-19
-3.1388E-18
-1.0532E-18 2.1287E-18 06 5.0829E-24 4.2187E-23 1.8191E-23
-2.5767E-23 0 -59035992.98 13545339.96 46133222.92 29096266.03 01 16269.17280
-3456.31260
-12649.42730
-8040.26920 02 -1.86675E+00 3.65109E-01 1.44409E+00 9.25007E-01 (t3) 03 1.14152E-04
-2.04170E-05
-8.78594E-05
-5.67107E-05 04 -3.92349E-09 6.36641E-10 3.00452E-09 1.95413E-09 85 7.18661E-14
-1.04784E-14
-5.47552E-14
-3.58824E-14 86 -5.48049E-19 7.09621E-20 4.15460E-19 2.74309E-19 8o -254239.875
-131133.94 54347.56810 21204.831 81 51.18680 25.97370 -10.94880
-4.64160 02 -4.27275E-03
-2.13339E-03 9.16309E-04 4.21932E-04 F t4t 03 1.89431E-07 9.31510E-08
-4.06793E-08
-2.02540E-08 04 -4.70515E-12
-2.28088E-12 1.01057E-12 5.41548E-13 05 6.20870E-17 2.96982E-17
-1.33232E-17
-7.64935E-18 86 -3.40068E-22
-1.60653E-22 7.28440E-23 4.46094E-23 Given the polynomial fits, the linearly interpolated temperature profile for any custom break size between 6 inches and 27.5 inches can be determined based on the location fraction between break sizes, and calculating the corresponding coefficients, as shown in the following equations (6): x--a L =- Equation 8 where: L = Location fraction Page 52 of 260 South Texas Project Risk-Informed GSI-191 Evaluation Volume 3: CASA Grande Analysis RI-GSI191-V03 Revision 1 x = Custom break size (in)a = Next smallest break size (in)b = Next largest break size (in)O'i = (1 -L) ' 0BL + L ' 6 B 2 ,, i = 0 ...6 Equation 9 where: 6', = Custom break size coefficients GB1, = Coefficients for next smallest break size GB2, = Coefficients for next largest break size Since the temperature profile is essentially the same for the 15-inch break and the 27.5-inch DEGB, it would be reasonable to use the 27.5-inch DEGB temperature profile breaks up to a 31-inch DEGB.This interpolation model was not fully implemented in the current evaluation.
Instead, the 6-inch break temperature profile was used to represent all small and medium breaks and the 27.5-inch DEGB temperature profile was used to represent all large breaks (see Assumption 1.j). The 6-inch break temperature profile was based on an extended simulation that went out to 30 days, and the 27.5-inch DEGB temperature profile was logarithmically extrapolated from 10 hours1.157407e-4 days <br />0.00278 hours <br />1.653439e-5 weeks <br />3.805e-6 months <br /> to 30 days as described in Assumption 1.k. The two temperature profiles that were used in the CASA evaluation are shown in Figure 2.2.3.Page 53 of 260 South Texas Project Risk-Informed GSI-191 Evaluation Volume 3: CASA Grande Analysis RI-GSI191-V03 Revision 1 Pool Temperature Profiles 200 180 inch Break-27.5-inch DEGB 160-16140!120 61, E 80 60 -------40 0.1 1 10 100 1000 Time (hr)Figure 2.2.3 -Temperature profiles implemented in CASA Grande 2.2.8 Operating Trains In the event of a LOCA, all three trains of ECCS and CSS would be automatically initiated due to a safety injection actuation signal and would begin to draw flow from the RWST (39). If all three CS pumps start successfully, operators would (per procedure) manually secure one of the three CS pumps (33). Once the RWST has been drained down to the Lo-Lo RWST level, the recirculation mode of ECCS operation would be automatically initiated through the three ECCS sumps (39).A variety of train or pump failure combinations are possible (many of which go beyond traditional design basis analyses).
This is discussed in more detail in Section 5.1.2.2.9 ECCS and CSS Flow Rates The maximum flow rates per train are 2,800 gpm for the low head safety injection (LHSI) flow (40), 1,620 gpm for the high head safety injection (HHSI) flow (40), and 2,600 gpm for the containment spray (CS)flow (40). This gives a maximum total sump flow of 7,020 gpm per train. The maximum total flow rates Page 54 of 260 South Texas Project Risk-Informed GSI-191 Evaluation Volume 3: CASA Grande Analysis RI-GSI191-V03 Revision 1 are only possible for LBLOCA conditions.
For SBLOCA conditions, containment sprays would not be initiated due to the small increase in containment pressure (5), the LHSI may not inject due to high RCS pressure, and the HHSI flow rate would vary from 0 gpm to 1,620 gpm per train depending on the actual size of the break and number of trains operating.
For MBLOCA conditions, the sprays would be initiated, but the combined LHSI and HHSI flow would range up to 4,420 gpm per train (40) depending on the actual size of the break. Table 2.2.12 provides a summary of the total SI flow rates for different break sizes based on thermal-hydraulic modeling 6 (5).Table 2.2.12 -Total SI flow rates Break Size Nominal Total Sl (in) Flow (gpm)1.5'" 1,231 2" 2,076 4" 4,120 6" 7,951 8" 10,285 15" 11,780 27.5" DEGB 12,060 The data in Table 2.2.12 is plotted in Figure 2.2.4 with the 27.5-inch DEGB plotted with the equivalent break size of 38.9 inches. As shown in this figure, the SI flow rate can be approximated using two linear curves (see Equation 10). The reason that the slope changes for breaks greater than approximately 9 inches is that the break size is large enough for the LHSI and HHSI pumps to operate at essentially maximum capacity.
For smaller breaks, the reduced break size causes back-pressure in the RCS that limits the total SI pump flow.6 These flow rates are based on simulations using nominal operating conditions (i.e. all ECCS trains operating, all fan coolers operating, and nominal CCW heat exchanger temperatures).
Page 55 of 260 South Texas Project Risk-Informed GSI-191 Evaluation Volume 3: CASA Grande Analysis RI-GS1191-V03 Revision 1 Sl Flow Rate 14,000 y = 11.715x + 11604 R 2 = 1 12,000 10,000 i y = 1247.2x R 2=0.972 5 (9.39 in,11,714 gpm)8,000 6,000 4,000 -2,000 0 0 5 10 15 20 25 30 35 40 45 50 Break Size (in)Figure 2.2.4 -Total SI flow rate vs. break size QTSJ = 1,247.2 gpm/in Dbreak QTSI = 1 gPmin'Dbreak
+ 11,604gpm if Dbreak < 9.39 in if Dbreak _ 9.39 in Equation 10 where: QTSl = Total SI flow rate (combined LHSI and HHSI pump flow rates from all trains)Dbreak = Break diameter (equivalent break diameter for DEGB)Note, however, that the total Sl flow rate cannot be greater than the maximum capacity of the operating pumps. Therefore, the following criterion is defined for the total SI flow rate based on a maximum LHSI pump flow rate of 2,800 gpm, and a maximum HHSI pump flow rate of 1,620 gpm (40): QTSI !5 2,800gpm" NLHSI + 1,620gpm NHHSJ Equation 11 Page 56 of 260 South Texas Project Risk-Informed GSI-191 Evaluation Volume 3: CASA Grande Analysis RI-GSI191-V03 Revision 1 where: NLHSI -Number of operating LHSI pumps NHHSI= Number of operating HHSI pumps For any given scenario, the flow rate for individual SI pumps within each train can be estimated based on a ratio of the maximum pump capacities, as well as the number of LHSI and HHSI pumps that are running. This is shown in the following equations:
I-2.800anmlrf 1 QLHI =QTS j2,800gpin -NLHS;+ 1,620gpm n NHHSI]Equation 12 Equation 13 r" 1 .2fl2nnn"1 QHHsI = QTS< "2,800gpm
- NLHSI + 1, 6 2 0gpm. N -SI where: QLHS, = LHSI pump flow rate for an individual train QHHSI= HHSI pump flow rate for an individual train If containment sprays are initiated, the flow rate is not dependent on the size of the break. However, it would vary depending on the number of trains in operation.
As discussed above, the maximum spray flow rate for a single train is 2,600 gpm. If all three trains are operating, the maximum flow rate is approximately 2,060 gpm per train (40). If two trains are operating, the maximum flow rate is approximately 2,350 gpm per train (41). The minimum probable CS flow rates are approximately 1,657 gpm per train for three train operation and 1,932 gpm per train for two train operation (41). The minimum spray flow rate for one train operation was not available in STP documentation, but was assumed to be 80% of the maximum flow rate consistent with the range of flow rates for two and three train operation (see Assumption 1.h). This gives a minimum spray flow rate of 2,080 gpm for single train operation.
Table 2.2.13 provides a summary of the range of containment spray flow rates.Table 2.2.13 -Containment spray flow rates Minimum Spray Maximum Spray Number of Operating Flow per Train Flow per Train Spray Pumps (gpm) (gpm)One Train 2,080 2,600 Two Trains 1,932 2,350 Three Trains 1,657 2,060 Page 57 of 260 South Texas Project Risk-Informed GSI-191 Evaluation Volume 3: CASA Grande Analysis RI-GSI191-V03 Revision 1 2.2.10 Qualified Coatings Quantity The total quantity of qualified coatings debris is a function of break size, location, surface area of coated concrete and steel within the ZOI, and coating thickness.
The quantity of qualified coatings debris generated was conservatively calculated for four break sizes as shown in Table 2.2.14 (11). The break sizes include a 2-inch break, a 6-inch break, a 15-inch break, and a 31-inch double-ended guillotine break (DEGB). The results can be conservatively applied for breaks in any location that are less than or equal to break sizes listed (e.g. the 15-inch quantities can be used for any breaks between 6 and 15 inches in diameter).
Table 2.2.14 -Quantity of qualified coatings debris 31-inch DEGB 15-inch Break 6-inch Break 2-inch Break Quantity (Ibm) Quantity (Ibm) Quantity (Ibm) Quantity (Ibm)Qualified Epoxy 105 25 3 0 Qualified IOZ 39 3 0 0 2.2.11 Unqualified Coatings Quantity The total quantity and locations of potentially transportable unqualified coatings are shown in Table 2.2.15 (12). Note that these coatings are listed as potentially transportable since unqualified coatings in upper containment would not transport if they fail after containment sprays are secured, and unqualified coatings in the reactor cavity would not transport for breaks outside the reactor cavity. This is discussed in more detail in Section 2.2.24 and Section 5.6.Table 2.2.15 -Quantity and location of potentially transportable unqualified coatings debris Upper Lower Reactor Total Coatings Type Containment Containment Cavity Quantity (Ibm)Quantity (Ibm) Quantity (Ibm) Quantity (Ibm)Unqualified Epoxy 295 (15%) 36 (2%) 1,574 (83%) 1,905 Unqualified IOZ 305 (83%) 64 (17%) 0 (0%) 369 Unqualified Alkyd 146 (54%) 125 (46%) 0 (0%) 271 Unqualified Baked Enamel 0 (0%) 267 (100%) 0 (0%) 267 Unqualified Intumescent 0 (0%) 2 (100%) 0 (0%) 2 The quantity of unqualified coatings debris that transports to the strainers is dependent on the failure fraction and failure timing. It is possible that some unqualified coatings would experience significantly less than 100% failure. For example, the unqualified epoxy in the reactor cavity at STP is actually a qualified coatings system, and would likely remain fully intact under post-LOCA conditions.
However, these coatings are conservatively assumed to be unqualified due to higher radiation exposure (12). The failure fraction probability distributions are shown in Table 2.2.16 and Figure 2.2.5 for unqualified epoxy Page 58 of 260 South Texas Project Risk-Informed GSI-191 Evaluation Volume 3: CASA Grande Analysis RI-GSI191-V03 Revision 1 coatings, Table 2.2.17 and Figure 2.2.6 for unqualified IOZ coatings, and Table 2.2.18 and Figure 2.2.7 for unqualified alkyd and baked enamel coatings (12). The intumescent coatings are assumed to be negligible (see Assumption 4.c). The unqualified coatings failure timing is provided in Table 2.2.19 (12).Table 2.2.16 -Epoxy failure fraction probability distribution inputs Failure Fraction Probabilit (Ffail) Probability 0.0% 0.0000 10.1% 0.0000 100.0% 0.0222 Epoxy 0.0250 0.0200 k 0.0150 h 0.0100 0.0050 0.0000.0.0 10.0 20.0 30.0 40.0 50.0 60.0 70.0 80.0 90.0 100.0% Failure Figure 2.2.5 -Epoxy failure fraction probability distribution Table 2.2.17 -IOZ failure fraction probability distribution inputs Failure Fraction Probability (Fban) Probability 0.0% 0.000000 20.8% 0.000000 100.0% 0.025254 Page 59 of 260 South Texas Project Risk-Informed GSI-191 Evaluation Volume 3: CASA Grande Analysis RI-GS1191-V03 Revision 1 IOZ I.9 0.03 0.025 0.02 -4 0.015 -0.01 0.005 0 0 10 20 30 40 50 60% Failure 70 80 90 100 Figure 2.2.6 -IOZ failure fraction probability distribution Table 2.2.18 -Alkyd and baked enamel failure fraction probability distribution inputs Failure Fraction Probability (Ff 6 1) Probability 0.0% 0.000000 5.0% 0.010207 100.0% 0.010308 Page 60 of 260 South Texas Project Risk-Informed GSI-191 Evaluation Volume 3: CASA Grande Analysis RI-GSI191-V03 Revision 1 Alkyd 0.012 0.01 0.008 0.006 0.004 0 I I I I I I 0.002 0 0 10 20 30 40 50% Failure 60 70 80 90 100 Figure 2.2.7 -Alkyd and baked enamel failure fraction probability distribution Page 61 of 260 South Texas Project Risk-Informed GSI-191 Evaluation Volume 3: CASA Grande Analysis RI-GSI191-V03 Revision 1 Table 2.2.19 -Time dependent failure fraction of unqualified coatings Time Dependent Time (Hours) Failure 0-24 0.060 Ffail 24-48 0.067 Ffail 48-72 0.054 Ffail 72-96 0.054 Ffail 96-124 0.107 Ffail 124-148 0.040
- Ffail 148-172 0.047 FfaiI 172-192 0.040 Ffa, 192-216 0.040" Ffail 216-240 0.040 Ffail 240-264 0.034 Ffail 264-288 0.034- Ffail 288-312 0.034 Ffail 312-336 0.034 Ffail 336-360 0.027. Ffail 360-384 0.027. Ffai 384-408 0.027 Ffail 408-432 0.027 Ffail 432-456 0.027 Ffail 456-480 0.020 Ffa, 480-504 0.020 Ffail 504-528 0.020 Ffail 528-552 0.020. Ffail 552-576 0.020" Ffail 576-600 0.013
- Ffail 600-624 0.013 Fflail 624-648 0.013 Ffai 648-672 0.013 FfaiI 672-696 0.013 Ffail 696-720 0.013 FfaiI Total 1.0 -Ffal The unqualified alkyd and IOZ coatings would fail as fines, but the unqualified epoxy coatings would fail in the distribution shown in Table 2.2.20 (12).Page 62 of 260 South Texas Project Risk-Informed GSI-191 Evaluation Volume 3: CASA Grande Analysis RI-GSI191-V03 Revision 1 Table 2.2.20 -Unqualified epoxy debris size distribution Size Designation Size Range Percentage of Total Mass (inches)Fines (particles) 0.006 12.28%Flat Fine Chips 0.0156 37.23%Flat Small Chips 0.125-0.5 9.43%Flat Large Chips 0.5-2.0 20.53%Curled Chips 0.5-2.0 20.53%2.2.12 Crud Debris Quantity The maximum quantity of RCS crud debris that would be released in a LOCA is 24 Ibm (13).2.2.13 Latent Debris Quantity The total quantity of latent debris is shown in Table 2.2.21 (42).Table 2.2.21 -Quantity of latent debris Coatings Type Quantity (all breaks)Coatngs ype(Ibm)Latent Fiber 30 Dirt/Dust 170 2.2.14 Miscellaneous Debris Quantity The total quantity of unqualified tags, labels, plastic signs, tie wraps, etc. at STP is bounded by a total surface area of 100 ft 2 (42).2.2.15 Insulation Destruction Pressure The insulation zones of influence (ZOls) used for this analysis are based on the standard deterministic approach described in NEI 04-07 Volumes 1 and 2, where the ZOI size for each type of insulation is based on the destruction pressure (43; 44). Table 2.2.22 lists the destruction pressures and ZOI sizes for insulation at STP.Page 63 of 260 South Texas Project Risk-Informed GSI-191 Evaluation Volume 3: CASA Grande Analysis RI-GSI191-V03 Revision 1 Table 2.2.22 -Input variables used primarily in debris penetration and core blockage analysis Destruction Pressure ZOI Radius/ Reference Insulation Type (psig) Break Diameter Transco RMI 114 2.0 (44)Unjacketed Nukon, Jacketed Nukon with 6 17.0 (44)standard bands Thermal-Wrap; assumed to be the same as Nukon (see 6 17.0 (44)Assumption 1.d)Microtherm; assumed to be the same as Min-K (see 2.4 28.6 (44)Assumption 4.a)2.2.16 Insulation Debris Size Distribution The debris size distribution used for low density fiberglass (LDFG) insulation (Nukon and Thermal-Wrap) is based on a proprietary methodology report where debris that is generated closest to the break consists of a larger fraction of fines and small pieces, and debris generated at the outer portion of the ZOI consists of a larger fraction of large pieces and intact blankets.
The fiberglass size distribution that was implemented in CASA Grande is shown in Table 4.1 of the Alion debris size distribution report (45).The Microtherm debris was assumed to fail as 100% fines, but was split into the following categories based on the manufacturing data: 58% SiO 2 , 39% TiO 2 , and 3% fibers (42).2.2.17 Debris Characteristics Table 2.2.23 provides the material properties (size and density) for insulation (42), qualified coatings (11; 42), unqualified coatings (12), crud (13), and latent debris (42) at STP.Page 64 of 260 South Texas Project Risk-Informed GSI-191 Evaluation Volume 3: CASA Grande Analysis RI-GS1191-V03 Revision 1 Table 2.2.23 -Material properties of debris Debris Type Debris Size Macroscopic Microscopic Density Density Fines: 7 pIm fibers Small Pieces: <6 inches Nukon Large Pieces: >6 inches 2.4 Ibm/ft 3 175 Ibm/ft 3 Jacketed Large Pieces: Intact Blankets Fines: 7 pm fibers Small Pieces: <6 inches Thermal-Wrap Large Pieces: >6 inches 2.4 Ibm/ft 3 159 Ibm/ft 3 Jacketed Large Pieces: Intact Blankets Fines: 6 pm fibers 165 Ibm/ft 3 Microtherm Fines: 20 pIm Si0 2 particles 15 Ibm/ft 3 137 Ibm/ft 3 Fines: 2.5 pm TiO 2 particles 262 Ibm/ft 3 Qualified Epoxy Fines: 10 pm particles 94 Ibm/ft 3 Qualified IOZ Fines: 10 pIm particles 208 Ibrm/ft 3 Fines: 6 mil particles Fine Chips: 0.0156"x15 mil Unqualified Epoxy Small Chips: 0.125"-0.5"x15 mil -124 Ibm/ft 3 Large Chips: 0.5"-2.0"x15 mil Curled Chips: 0.5"-2.0"x15 mil Unqualified Alkyd Fines: 4 -20 pm particles 207 Ibmft 3 Unqualified IOZ Fines: 4 -20 pm particles 244 Ibm/ft 3 Unqualified Baked Enamel Fines: 4 -20 Ipm particles 93 Ibmft 3 Crud Fines: 8 -63 pm particles
-325 -556 Ibm/ft 3 Latent Fiber Fines: 7 pIm fibers 2.4 Ibm/ft 3 175 Ibm/ft 3 Dirt/Dust Fines: 17.3 pm particles 169 Ibm/ft 3 2.2.18 Initial Pool Chemistry The initial pool chemistry is a function of the volume of water, quantity of buffer, and concentration of boron, lithium, and/or silica in the RWST, RCS, and accumulators.
This input is not currently used for CASA Grande since a simplified conservative approach was used to quantify chemical effects in this analysis.Page 65 of 260 South Texas Project Risk-Informed GSI-191 Evaluation Volume 3: CASA Grande Analysis RI-GSI191-V03 Revision 1 2.2.19 Pool pH The pool pH is a function of the trisodium phosphate (TSP) dissolution rate, the boron concentration, the pool volume, and long-term acid formation due to radiolysis.
This input is not currently used for CASA Grande since a simplified conservative approach was used to quantify chemical effects in this analysis.2.2.20 Metal Quantity The types of metal in containment include galvanized steel, aluminum, lead, copper, etc. These metals may be submerged in the pool or exposed to containment sprays, and some types of metal can significantly influence chemical effects.This input is not currently used for CASA Grande since a simplified conservative approach was used to quantify chemical effects in this analysis.2.2.21 Blowdown Transport Fractions The blowdown transport fractions were calculated based on the break location, size of debris, upper and lower containment volumes, and the locations of grating. The appropriate blowdown transport fractions are shown for each break location and debris size in Table 2.2.24 (23).The types of debris that would be subject to the blowdown forces include Nukon, Microtherm, qualified coatings, and crud. As discussed in Section 5.4.2, the Nukon debris would fail as fines, small pieces, large pieces, and intact blankets.
The Microtherm, qualified coatings, and crud debris would all fail as fine debris and would transport similar to the Nukon fines. Since the intact blankets would not transport readily, this debris was not included in the transport analysis (see Assumption 6.a).Based on the weld locations and transport potential, all LOCA breaks were binned in the following location categories:
- 1. Steam generator compartments:
Weld locations inside the secondary shield wall above Elevation 19'-0".2. Reactor cavity: Weld locations inside the primary shield wall.3. Below Steam Generator Compartments:
Weld locations inside the secondary shield wall below Elevation 19'-0".4. Pressurizer compartment:
Weld locations inside the pressurizer compartment (excluding the surge line).5. Pressurizer surge line: Weld locations on the surge line outside the secondary shield wall.6. RHR compartments:
Weld locations inside the RHR compartments.
Page 66 of 260 South Texas Project Risk-Informed GSI-191 Evaluation Volume 3: CASA Grande Analysis RI-GSI191-V03 Revision 1 7. Annulus: Weld locations in the annulus (excluding the surge line).Table 2.2.24 -Blowdown transport fractions according to break location Debris Type and Blowdown Transport Fractions Break Location Size Upper Lower Remaining in Containment Containment Compartments
- 1. Steam Fines 70% 30% 0%Generator Small LDFG 33-60% 13-25% 15-54%Compartments Large LDFG 0-22% 0% 78-100%Fines 70% 30% 0%2. Reactor Cavity Small LDFG 33-60% 13-25% 15-54%Large LDFG 0-22% 0% 78-100%3. Below Steam Fines 70% 30% NA Generator Small LDFG 21-50% 50-79% NA Compartments Large LDFG 0% 100% NA Fines 70% 30% 0%4.mpresi Small LDFG 26-66% 11-28% 6-63%Large LDFG 16-26% 1-11% 63-83%Fines 70% 30% NA 5Presuize Small LDFG 3-36% 64-97% NA Surge Line Large LDFG 0% 100% NA Fines 70% 30% 0%6.prHR Small LDFG 3-45% 1-19% 36-96%Large LDFG 0% 0-10% 90-100%Fines 70% 30% 0%7. Annulus Small LDFG 6-37% 13-25% 38-81%Large LDFG 0% 0% 100%2.2.22 Washdown Transport Fractions The washdown transport fractions were calculated based on the spray flow distribution, the size of debris, and the number of grating levels that debris would be washed through. The appropriate washdown transport fractions are shown for each debris size depending on whether sprays are initiated in Table 2.2.25 (23). Note that the washdown transport fractions do not depend on the location of the break, but only whether sprays are initiated.
Since unqualified coatings debris may fail later in the event, this debris would only be washed down to the pool if the sprays are initiated and the coatings fail before the sprays are secured.Page 67 of 260 South Texas Project Risk-Informed GSI-191 Evaluation Volume 3: CASA Grande Analysis RI-GSI191-V03 Revision 1 Table 2.2.25 -Washdown transport fractions according to spray initiation Sprays Washdown Transport Fraction Sprays Debris Type Washed Down in Washed Down inside Initiated?
Annulus Secondary Shield Wall Fines 47% 53%Yes Small LDFG 7-19% 21-27%Large LDFG 0% 0%No All 0% 0%2.2.23 Pool Fill Transport Fractions The pool fill transport fractions were calculated based on the size of debris, the break location, the volume of the inactive cavities and sump cavities, and the pool volume at the time when these cavities would be filled. The appropriate pool fill transport fractions are shown for each break location and debris size in Table 2.2.26 (23).Table 2.2.26 -Pool fill transport fractions according to break location Break Location Debris Pool Fill Transport Fraction Type Each Sump Inactive Cavities Breaks Inside the Fines (all) 2% 5%Secondary Shield Wall Small LDFG 0% 0%(Locations 1-3) Large LDFG 0% 0%Break Outside the Fines (all) 3% 9%Secondary Shield Wall Small LDFG 0% 0%(Locations 4-7) Large LDFG 0% 0%2.2.24 Recirculation Transport Fractions The transport of debris during the recirculation phase is dependent on the break location, water level, and flow rate. The transport fractions were calculated based on CFD modeling of the recirculation pool.Since it is not practical to run CFD simulations for all possible scenarios to investigate the effects of differing water levels and flow rates, a limited number of simulations were completed to determine recirculation transport fractions for various groups of breaks. The appropriate recirculation transport fractions are shown for each break location and debris size in Table 2.2.27 and Table 2.2.28 (23). Note that the unqualified epoxy coatings in the reactor cavity would not transport for any breaks outside the reactor cavity. In the case of a reactor cavity break, the transport fractions for the unqualified epoxy in the reactor cavity are the same as the unqualified epoxy outside the reactor cavity (23).Page 68 of 260 South Texas Project Risk-Informed GSI-191 Evaluation Volume 3: CASA Grande Analysis RI-GSI191-V03 Revision 1 Table 2.2.27 -Recirculation pool transport fractions according to break size and location (insulation)
Recirculation Transport Fraction Break Break Debris in Washed in Washed inside Location Size Lower Annulus Secondary Containment Shield Wall Fines 100% 100% 100%SBLOCA Small LDFG 27% 20% 27%1: Steam Generator Large LDFG 0% NA NA Fines 100% 100% 100%Compartments MBLOCA Small LDFG 64% 58% 64%LBLOCA Large LDFG 0% NA NA 2: Reactor SBLOCA Fines 100% 100% 100%Cavity MBLOCA Small LDFG 64% 58% 64%LBLOCA Large LDFG 0% NA NA Fines 100% 100% 100%3: Below SBLOCA Small LDFG 27% 20% 27%Steam Large LDFG 0% NA NA Generator Fines 100% 100% 100%MBLOCA Compartments Small LDFG 64% 58% 64%LBLOCA Large LDFG 0% NA NA 4: Pressurizer SBLOCA Fines 100% 100% 100%Compartment MBLOCA Small LDFG 61% 55% 16%LBLOCA Large LDFG 0% NA NA 5: Pressurizer SBLOCA Fines 100% 100% 100%Surge Line MBLOCA Small LDFG 61% 55% 16%LBLOCA Large LDFG 0% NA NA/6: RHR SBLOCA Fines 100% 100% 100%Compartments MBLOCA Small LDFG 61% 55% 16%LBLOCA Large LDFG 26% NA NA SBLOCA Fines 100% 100% 100%7: Annulus MBLOCA Small LDFG 61% 55% 16%LBLOCA Large LDFG NA NA NA Page 69 of 260 South Texas Project Risk-Informed GSI-191 Evaluation Volume 3: CASA Grande Analysis RI-GSI191-V03 Revision 1 Table 2.2.28 -Recirculation transport fractions according to break size and location (coatings, latent debris, crud, dirt/dust)
Recirculation Transport Fraction Break Debris in Washed Washed Break Location Bre Debris Type Size Lower in inside Size Containment Annulus Secondary Shield Wall Qual. Coatings Fines 100% 100% 100%Unqual. Coatings Fines 100%Fine Chips 21%Unqual. Epoxy Small Chips 0%SBLOCA Large Chips 0%Curled Chips 100%Crud Fines 100% 100% 100%Breaks Inside Dirt/Dust Fines 100% 100% 100%the Secondary Latent Fiber Fines 100% 100% 100%Shield Wall Qual. Coatings Fines 100% 100% 100%(Locations 1-3) Unqual. Coatings Fines 100%Fine Chips 41%Small Chips 0%MBLOCA Unqual. Epoxy Larg Chips 0%LBLOCA Large Chips 0%Curled Chips 100%Crud Fines 100% 100% 100%Dirt/Dust Fines 100% 100% 100%Latent Fiber Fines 100% 100% 100%Qual. Coatings Fines 100% 100% 100%Unqual. Coatings Fines 100%Fine Chips 31%Breaks Outside Fine Chips 0%the Secondary MBLOCA Unqual. Epoxy Small Chips 0%Shield Wall LBLOCA Large Chips 0%(Locations 4-7) Curled Chips 100%Crud Fines 100% 100% 100%Dirt/Dust Fines 100% 100% 100%_Latent Fiber Fines 100% 100% 100%2.2.25 Debris Erosion Small or large pieces of fiberglass debris retained on grating in upper containment would be subject to erosion by containment sprays. Small or large pieces of fiberglass debris that settle in the containment pool would also be subject to erosion by the flow of water moving past the debris. The erosion fraction for fiberglass debris retained in upper containment debris would be 1%, and the average erosion Page 70 of 260 South Texas Project Risk-Informed GSI-191 Evaluation Volume 3: CASA Grande Analysis RI-GS1191-V03 Revision 1 fraction for fiberglass debris that settles in the recirculation pool would be a range below 10% as documented in Table 6.6 of the STP debris transport calculation (23).The spray erosion would occur relatively quickly in the event, and can be assumed to occur during the pool fill phase (23). However, the erosion of fiberglass debris in the pool would be a more gradual process. As shown in Table 6.6 of the STP debris transport calculation, the majority of erosion would occur within the first 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />, but some erosion would continue at reduced rates over the duration of the event (23).2.2.26 Strainer Geometry The strainers at STP are PCI Sure-Flow stacked disk strainers.
The gap thickness between the strainer disks is 1 inch (46). The total surface area of each strainer is 1,818.5 ft2 per train, the interstitial volume is 81.8 ft 3 per train, and the circumscribed strainer area is 419.0 ft 2 per train (47). The height of the strainers above the containment floor is 28.5 inches (48), and the center of the strainers is 15.4 inches above the floor (48). The minimum water level required to flow through the bottom of the strainer core tube (10-7/8" OD) and fill the sump pits is 10 inches (47; 46). The strainer hole size is 0.095 inches (49).The inner diameter of the ECCS sump suction pipes is 15.25 inches (50; 51). The length and width of the sump pits are 10 ft by 4 ft (48).Figure 2.2.8 through Figure 2.2.11 show photos of the STP strainers.
As shown in Figure 2.2.9, protective grating was installed in front of the exposed strainer area to prevent inadvertent damage during outages. The location of the strainers in containment is shown in Section 5.2 (Figure 5.2.7).Page 71 of 260 South Texas Project Risk-Informed GSI-191 Evaluation Volume 3: CASA Grande Analysis RI-GSI191-V03 Revision 1 Figure 2.2.8 -STP strainer Photo 1 (before protective grating was installed)
Figure 2.2.9 -STP strainer Photo 2 (after protective grating was installed)
Figure 2.2.10 -STP strainer Photo 3 Page 72 of 260 South Texas Project Risk-Informed GSI-191 Evaluation Volume 3: CASA Grande Analysis RI-GSI191-V03 Revision 1 Figure 2.2.11 -STP strainer Photo 4 2.2.27 Clean Strainer Head Loss Clean strainer head loss (CSHL) is a function of the strainer geometry, sump flow rate, and pool temperature.
Table 2.2.29 shows the measured clean strainer head loss data based on a test with a prototype strainer module (52).Table 2.2.29 -Clean strainer head loss Test Module Flow Full Strainer Flow Test Temperature Measured Head Rate (gpm) Rate7 (gpm) (°F) Loss (ft)176.58 3,511.7 117.2 0.02591 265.15 5,273.1 116.6 0.05073 353.05 7,021.3 116.3 0.09231 441.30 8,776.4 116.1 0.14424 530.13 10,542.9 115.9 0.21946 7 The full strainer flow rate was calculated by scaling the test flow rate up using the test module surface area of 91.44 ft2 (17) and the full strainer surface area of 1,818.5 ft 2 (15).Page 73 of 260 South Texas Project Risk-Informed GSI-191 Evaluation Volume 3: CASA Grande Analysis RI-GSI191-V03 Revision 1 2.2.28 Pump NPSH Margin Pump NPSH margin is equal to the NPSH available minus the NPSH required.
NPSH available is dependent on the containment pressure, pool temperature, water level, and piping losses, and excludes clean strainer head loss and debris bed head loss. The NPSH required is dependent on the pump requirements and the void fraction at the pump inlet. A detailed evaluation was performed for STP (25), and the equations used to calculate NPSH margin are shown in Section 5.7.5.The NPSH required for the HHSI, LHSI, and CS pumps is 12 ft (25). The difference in elevation between the containment floor and the pump impellers is 25.65 ft (25).2.2.29 Strainer Structural Margin The strainers have been structurally qualified for head losses up to 4.00 psi differential pressure at 128'F (53; 54), which is equivalent to a head loss of 9.35 ft.2.2.30 Vortex Air Ingestion Vortex formation is precluded based on the design of the STP strainers (55).2.2.31 Bubble Transport Partial bubble transport can occur in a horizontal pipe when the Froude number is greater than 0.35, and full transport will occur when the Froude number is greater than 0.55 (56). For vertical pipes, partial transport will occur when the Froude number is greater than 0.35, and full transport will occur when the Froude number is greater than 1.0 (56).2.2.32 Pump Gas Limits The HHSI, LHSI, and CS pumps at STP can withstand gas voids up to 10% for up to 5 seconds depending on the pump flow rate compared to the best efficiency point (BEP) for the pump (57). The acceptance criterion for a steady-state gas void fraction at the pump suction inlet is 2% (58).2.2.33 Fiberglass Penetration The input parameters for filtration and shedding of fiberglass debris at the strainer were defined based on prototype strainer module testing (59). The filtration efficiency can be described as shown in Equation 14.fr(Ms + b if 0 < Ms < ME if(Mc) + (1 -f(M,)) (1 -e-8(MsMc))
if Ms > MC Page 74 of 260 South Texas Project Risk-Informed GSI-191 Evaluation Volume 3: CASA Grande Analysis RI-GS1191-V03 Revision 1 where: f = Filtration efficiency Ms = Mass of fiber on strainer m, b, Mc, 6 = Fitted filtration parameters The range of filtration coefficients from the test are shown in Table 2.2.30 Table 2.2.30 -Fitted filtration parameters for test module mtest (g-,) b 6 test (g-1) Mc,test (g)Lower 0.0003391 0.656 0.001308 880 Center 0.0003263 0.689 0.001125 930 Upper 0.0003723 0.706 0.031787 790 To use the test results, it is necessary to scale the parameters back to the plant conditions.
Parameter b (the filtration efficiency at clean strainer conditions) is dimensionless.
However, m, 6, and Mc have to be scaled proportional to the scaled strainer area. Given a test module area of 91.44 ft 2 and a strainer area of 1,818.5 ft 2 per train, the test parameters can be scaled to the plant conditions using the following equations.
Table 2.2.31 shows the adjusted parameters.
Amodule 91.44f t2 mstrainer
=mtest mAstraier test 1,818.5ft2 A module 91.44ft 2 Astrainer 1,s " = 6 test 1818.5ft 2 Astrainer 1,818.5ftz Mc strainer = Mc, test" A Mctest "' Anodule ' 91.44ft 2 Equation 15 Equation 16 Equation 17 Table 2.2.31 -Fitted filtration parameters for each ECCS strainer m (lbm 1 ,) b 6 (lbm',) M r (Ibm)Lower 0.007741 0.656 0.02968 38.5 Center 0.007449 0.689 0.02511 40.7 Upper 0.008499 0.706 0.7259 34.6 The shedding coefficients determined from the testing are shown in Table 2.2.32 (59). Note that the rq is reported as a dimensionless value in terms of qtesdhtest, where h is defined as the strainer flow rate divided by the pool volume (Q/V). This is discussed in more detail in Section 5.9.Page 75 of 260 South Texas Project Risk-Informed GSI-191 Evaluation Volume 3: CASA Grande Analysis RI-GSI191-V03 Revision 1 Table 2.2.32 -Fitted shedding parameters V ritest/htest Minimum 0.009561 0.07870 Average 0.015188 0.12466 Maximum 0.019618 0.12657 2.2.34 Decay Heat Curve As shown in Table 2.2.33, the decay heat generation rate was taken from the 1979 ANS plus 2 sigma uncertainty (60). The rated thermal power for STP is 3,853 MW (61).Table 2.2.33 -Decay heat generation rate based on 1979 ANS plus 2 sigma uncertainty Time Decay Heat Generation Rate (Btu/Btu)10 0.053876 15 0.050401 20 0.048018 40 0.042401 60 0.039244 80 0.037065 100 0.035466 150 0.032724 200 0.030936 400 0.027078 600 0.024931 800 0.023389 1000 0.022156 1500 0.019921 2000 0.018315 4000 0.014781 6000 0.013040 8000 0.012000 10000 0.011262 15000 0.010097 20000 0.009350 Page 76 of 260 South Texas Project Risk-Informed GSI-191 Evaluation Volume 3: CASA Grande Analysis RI-GSI191-V03 Revision 1 Time Decay Heat Generation Rate (Btu/Btu)40000 0.007778 60000 0.006958 80000 0.006424 100000 0.006021 150000 0.005323 400000 0.003770 600000 0.003201 800000 0.002834 1000000 0.002580 2.2.35 Core Blockage Debris Limits Based on conservative testing by the PWR Owner's Group (PWROG), debris loads greater than 15 grams per fuel assembly (g/FA) may cause issues with core blockage (62). STP has a total of 193 fuel assemblies (63). Therefore, the total fiber quantity required to meet the 15 g/FA limit is 2,895 g (6.4 Ibm).Page 77 of 260 South Texas Project Risk-Informed GSI-191 Evaluation Volume 3: CASA Grande Analysis RI-GSI191-V03 Revision 1 3 Assumptions This section lists the major assumptions made in the CASA Grande analysis.1. General Assumptions
- a. It was assumed that a LOCA that occurs during full power operation (i.e. Mode 1) is equivalent or bounding compared to the other operating modes. This is a reasonable assumption since the RCS pressure and temperature (key inputs affecting the ZOI size)would either be approximately the same or significantly lower for Modes 2 through 6.Also, the flow rate required to cool the core (a key input affecting core blockage) would be significantly reduced for low power or shutdown modes.b. It was assumed that containment would be isolated at the time of an accident.
Although containment overpressure was not credited (see Assumption 1.c), this is a best-estimate assumption that allows the containment pool temperature to be greater than 212 *F. In general, assuming a higher pool temperature at the beginning of the event is also conservative since corrosion and dissolution would be higher, NPSH margin would be lower, and degasification would be higher.c. Containment pressure was assumed to be 14.7 psia for all cases except when the pool temperature is higher than the boiling temperature.
In cases where the pool temperature is above 212 °F, the containment pressure was assumed to be equal to the saturation pressure.
This is a conservative assumption since neglecting containment overpressure reduces the ECCS pump NPSH margin and increases the amount of degasification at the strainer.d. It was assumed that Nukon and Thermal-Wrap are identical for GSI-191 analysis purposes since both are LDFG products with similar properties (43).e. It was assumed that small and large pieces of fiberglass that are predicted to transport to the strainer can be treated as fine debris with respect to both the transport timing and subsequent effects on head loss and penetration.
This is a conservative assumption since in reality, the pieces of insulation debris would tend to transport more slowly, would be less likely to penetrate the strainer, and would not form as uniform a debris bed on the strainer resulting in lower head losses.f. The only reflective metal insulation (RMI) in containment at STP is stainless steel Transco RMI that is installed on the reactor vessel (42). It was assumed that the RMI can be neglected in the STP GSI-191 analysis.
This is a reasonable assumption since 1) the quantity of RMI debris would be relatively small since the ZOI size for Transco RMI is only 2.0D (44), 2) stainless steel foils are chemically inert, 3) the majority of RMI debris generated would not reach the strainers since the transport paths from the reactor cavity through the secondary shield wall to the strainers are tortuous and not conducive to transport of the relatively heavy RMI debris (64), and 4) RMI has a minor effect on debris head loss for strainers that are sitting above the floor elevation (RMI can actually reduce head loss by breaking up the uniform accumulation of a fiber debris bed) (65).Page 78 of 260 South Texas Project Risk-Informed GSI-191 Evaluation Volume 3: CASA Grande Analysis RI-GSI191-V03 Revision 1 g. It was assumed that the failure of permanently installed lead blankets within various break ZOls can be neglected.
This is a reasonable assumption since there are only a few pipes with lead blankets at STP, a limited number of breaks would be close enough to these pipes to damage the lead blankets, and the lead debris that is generated would not be likely to transport or cause any significant problems.
Note, however, that the fiberglass insulation underneath the lead shielding on the piping within the appropriate ZOI is considered for the debris generation calculation.
- h. It was assumed that the minimum spray flow rate for single train operation is 80% of the maximum spray flow rate for single train operation.
This is a reasonable assumption since the minimum spray flow rate for two train operation is 82% of the maximum spray flow rate for two train operation, and the minimum spray flow rate for three train operation is 80% of the maximum spray flow rate for three train operation (see Section 2.2.9).It was assumed that switchover to hot leg injection would occur 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> after the start of the event. This is a reasonably conservative assumption since the switchover procedure is started 5.5 hours5.787037e-5 days <br />0.00139 hours <br />8.267196e-6 weeks <br />1.9025e-6 months <br /> after the start of the event and according to plant personnel, switchover for both trains can be completed within 15 minutes (66).j. As shown in Table 2.1.1, the pool temperature has an effect on many aspects of the overall GSI-191 evaluation including chemical effects (material release rates and solubility limits), debris transport, strainer head loss, NPSH margin, degasification, and in-vessel effects. For some aspects of the analysis, a higher temperature profile is more conservative (e.g. NPSH margin and degasification), whereas a lower temperature profile is more conservative for other aspects of the analysis (e.g. strainer head loss and debris transport).
Due to the competing effects and the complexity of the overall evaluation, it is not possible to pre-determine whether a higher or lower pool temperature profile would be more limiting.
However, several aspects of the evaluation were analyzed independently and implemented in CASA without a direct link to the temperature profile. The effects of temperature on the various aspects of the evaluation are described below: 1. The chemical effects evaluation includes both an analysis of the release rates and the solubility limits. Release rates increase with increasing temperature, and solubility decreases with decreasing temperature (with the exception of products that exhibit retrograde solubility), so it is difficult to say which direction is conservative overall for chemical effects. However, since the STP CHLE testing hasn't been fully completed yet, a simplified approach was used to address chemical effects where chemical head loss was (mostly) decoupled from the temperature profile in CASA. As discussed in Section 5.7.3, chemical precipitation was assumed to occur when the pool temperature drops below 140 'F. Therefore, minimizing the temperature profile would be conservative.
II. The debris settling and tumbling velocities are lower at lower temperatures due to the higher viscosity, so minimizing the temperature profile would be conservative.
However, this effect has been decoupled from the temperature profile in CASA since the debris transport fractions were conservatively Page 79 of 260 South Texas Project Risk-Informed GSI-191 Evaluation Volume 3: CASA Grande Analysis RI-GS1191-V03 Revision 1 determined based on transport testing that was generally conducted at room temperature conditions (23).Ill. The clean strainer head loss and conventional debris bed head loss are higher at lower temperatures, so minimizing the temperature profile would maximize the overall strainer head loss.IV. The pump NPSH margin is lower at higher temperatures, so maximizing the temperature profile would be conservative.
However, the strainer structural margin is lower than the NPSH margin for essentially the entire event except very early in the event when the pool temperature is near or above 212 *F.V. The quantity of gas released at the strainer is larger at higher temperatures, so maximizing the temperature profile would tend to be conservative.
However, degasification is also larger for larger pressure drops, which increases at lower temperatures, so these two factors are competing.
In general, the void fraction does not change significantly over the range of prototypical long-term temperature profiles where the debris bed head loss would be more likely to be high enough for significant degasification to occur (i.e. due to the increase in head loss from chemical precipitates and failed unqualified coatings).
Additional sensitivity analysis needs to be conducted to fully understand the effects of the temperature profile on failures due to degasification.
However, in the current analysis, this was not considered to be a significant driver.VI. The conventional debris head loss within the core would be higher at lower temperatures similar to the strainer head loss. However, this temperature effect has been decoupled from the CASA temperature profile based on the core blockage acceptance criteria defined by testing and thermal-hydraulic modeling (see Section 5.11).VII. The boil-off rate (along with the corresponding SI flow split and debris transport to the core for a cold leg break during cold leg injection) increases with increasing temperature, so a higher temperature during the cold leg injection period is conservative.
However, this effect has been decoupled from the temperature profile implemented in CASA since the SI flow entering the vessel was assumed to be at saturation conditions (see Section 5.11.3).Based on this evaluation, it was assumed that all small and medium breaks less than 6 inches can be conservatively represented by a nominal 6-inch break containment pool temperature profile, and all large breaks greater than 6 inches can be represented by a nominal 27.5-inch DEGB temperature profile. As shown in Section 2.2.7, these two temperature profiles tend to maximize the temperature early in the event (i.e. the first 1-2 hours), and then minimize the temperature for the remainder of the event. This is generally conservative since the strainer debris head loss and chemical precipitation timing are the most significant parameters affected by the temperature profile and will be maximized if the temperature profile is minimized.
Page 80 of 260 South Texas Project Risk-Informed GSI-191 Evaluation Volume 3: CASA Grande Analysis RI-GSI191-V03 Revision 1 k. It was assumed that the temperature profiles developed from the thermal-hydraulic modeling can be logarithmically extrapolated from the temperature at the end of the simulations to the nominal component cooling water (CCW) temperature at 30 days-86 'F (5). This minimizes the long-term temperature profile since the containment pool temperature will never drop below the CCW temperature and is likely to be higher than the CCW temperature at the end of 30 days. As discussed in Assumption 1.j, minimizing the temperature profile is conservative.
I. It was assumed that a 36-hr run time for the CASA Grande simulations is sufficient to predict the scenarios that would proceed to failure. This is a reasonable assumption since most of the dominant time-dependent phenomena occur within the first 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />.2. Equipment Failure Assumptions (prior to the start of recirculation)
- a. It was assumed that pump failures in one train are indistinguishable from identical failures in another train. For example, a failure of the LHSI and CS pumps in Train A (with no other failures) is assumed to be identical to a failure of the LHSI and CS pumps in Train C (with no other failures).
This is a reasonable assumption since the strainer area and pump flow rates are the same for all three trains, and the trains are physically located in the same area in containment.
Therefore, there would be negligible differences in debris transport, head loss, penetration, etc. for cases with identical failures in different trains.b. It was assumed that a combination of pumps failing in the same train is worse than the same combination of pumps failing in separate trains. For example, given a scenario where one LHSI, one HHSI, and one CS pump all fail, the scenario where all three pumps fail in Train A is worse than the scenario where the HHSI and LHSI pumps fail in Train A and the CS pump fails in Train B. The total CS and SI flow would be the same for these two cases. In the first case, however, Trains B and C would be operating at maximum flow, whereas in the second case, only Train C would be operating at maximum flow and the remaining flow would be split between Trains A and B. As illustrated in Table 3.1, by splitting the flow between Trains A and B, the likelihood of either Train A or Train B failing due to high head loss or degasification is significantly reduced.Table 3.1 -Strainer debris accumulation and approach velocity comparison 8 Train/Parameters Scenario 1 Scenario 2 (LHSI A, HHSI A, CS A) (LHSI A, HHSI A, CS B)Train A Debris Accumulation 0% 19%Approach Velocity 0 ft/s 0.0032 ft/s Train B Debris Accumulation 50% 31%Approach Velocity 0.0086 ft/s 0.0054 ft/s Train C Debris Accumulation 50% 50%Approach Velocity 0.0086 ft/s 0.0086 ft/s 8 Calculated using a strainer area of 1,818.5 ft 2 per strainer and flow rates of 2,800 gpm per LHSI pump, 1,620 gpm per HHSI pump, and 2,600 gpm per CS pump.Page 81 of 260 South Texas Project Risk-Informed GSI-191 Evaluation Volume 3: CASA Grande Analysis RI-GSI191-V03 Revision 1 c. It was assumed that the failure of various combinations of pumps can be bounded in terms of strainer failures by other scenarios that have an equal or higher approach velocity and an equal or higher debris accumulation on any one strainer.
This assumption is appropriate based on the conservative assumptions that failure of one pump or train is equivalent to the failure of all pumps and trains (see Assumption 12.a through Assumption 12.c). This is illustrated in Table 3.2 using CS pump failures as an example. In this example, Train C in Scenario 3 has the most limiting conditions with the combination of highest debris accumulation and highest approach velocity, and therefore would be the most likely fail.Table 3.2 -Strainer debris accumulation and approach velocity comparison for CS pump failures 8 Scenario 1 Scenario 2 Scenario 3 Scenario 4 (no failures) (CS A) (CS A, CS B) (CS A, CS B, CS C)Train A Debris Accumulation 33.3% 24% 28% 33.3%Approach Velocity 0.0086 ft/s 0.0054 ft/s 0.0054 ft/s 0.0054 ft/s Train B Debris Accumulation 33.3% 38% 28% 33.3%Approach Velocity 0.0086 ft/s 0.0086 ft/s 0.0054 ft/s 0.0054 ft/s Train C Debris Accumulation 33.3% 38% 44% 33.3%Approach Velocity 0.0086 ft/s 0.0086 ft/s 0.0086 ft/s 0.0054 ft/s d. It was assumed that the failure of various combinations of pumps can be bounded in terms of in-vessel failures by other scenarios that have a higher flow split to the core with an equal number of trains in operation.
The flow split to the core is dependent on the flow split to the SI pumps vs. the total sump flow rate (QslQtota,), and the boil-off flow split to the core vs. the total Sl flow rate for cold leg breaks (QbOoi/QsI).
An example calculation is illustrated in the table below.Table 3.3 -Core debris accumulation for various pump failures 9 Scenario 1 Scenario 2 Scenario 3 Scenario 3 Scenario 3 Flow Splits (1 CS) (1 LHSI, 1CS) (1 HHSI, 1CS) (2 CS) (2 LHSI, 1 CS)SI Flow Split 71.8% 66.8% 69.1% 83.6% 59.6%Core Flow Split 4.5% 5.7% 5.2% 4.5% 7.8%Total Split 3.3% 3.8% 3.6% 3.8% 4.7%e. It was assumed that failure of equipment other than pumps does not need to be explicitly linked to the PRA equipment failure probabilities.
Failures of fan coolers and heat exchangers can have a significant impact on the containment pool temperature.
However, rather than modeling the explicit equipment failure scenarios postulated in 9 Calculated for cold leg break conditions with three train operation using flow rates of 2,800 gpm per LHSI pump, 1,620 gpm per HHSI pump, 2,600 gpm per CS pump, and a 600 gpm boil-off flow rate.Page 82 of 260 South Texas Project Risk-Informed GSI-191 Evaluation Volume 3: CASA Grande Analysis RI-GSI191-V03 Revision 1 the PRA, the range of equipment failures was considered in the development of the containment pool temperature profiles (5).f. It was assumed that pump failure scenarios with a frequency less than 2E-09/yr would result in strainer blockage, core blockage, or boron precipitation for all medium and large breaks. This is a conservative assumption since the available pumps for these scenarios would generally be capable of mitigating most of these events.3. LOCA Frequency Assumptions
- a. It was assumed that the geometric-mean aggregation of LOCA frequencies in NUREG-1829 (37) is the most appropriate set of results to use for this evaluation.
As described in Section 5.3, the NUREG-1829 data must be fit to appropriately determine the epistemic uncertainty associated with LOCA frequency estimates.
The geometric-mean aggregation is more appropriate than an arithmetic-mean aggregation or other method since the geometric-mean aggregation produces frequency estimates that are approximately the same as the median estimates of the panelists.
Other aggregation methods may result in more conservative frequencies, but would tend to deviate from the overall consensus of the panelists.
- b. It was assumed that the current-day LOCA frequencies are more appropriate to use for this evaluation than the end-of-plant-license frequencies.
This is a reasonable assumption for the base analysis, although the effect of using end-of-plant-license frequencies can be evaluated as a sensitivity case.c. It was assumed that breaks on non-weld locations can be excluded from the evaluation.
This is a reasonable assumption since the break frequency for non-weld locations would be significantly smaller than weld locations, and would not generate significantly different quantities of debris from the weld breaks. It was also assumed that isolable breaks can be excluded from the evaluation since isolable breaks would not lead to recirculation.
- d. It was assumed that LOCA frequencies can be linearly interpolated.
This is a conservative assumption since the frequencies generally exhibit an exponentially decreasing trend as break size increases.
- e. Out of 193 welds on small bore (0.75-inch and 1-inch) pipes, only 35 were modeled with 3 welds modeled on 1-inch pipes and 32 welds modeled on 0.75-inch pipes (4). It was assumed that the overall break frequency for the 193 welds can be distributed across the 35 welds (176 welds assumed to be 0.75-inch and 17 welds assumed to be 1-inch).This is a reasonable assumption since breaks of this size are generally insignificant with respect to GSI-191 phenomena.
Also, since the 35 welds that were modeled are scattered around containment, it is not likely that the weld locations that were not modeled would have any significant differences with respect to the quantity of debris that would be generated or transported from the locations that were modeled.f. With exception to the small bore weld count discussed in Assumption 3.e, it was assumed that the weld count in the CAD model (4) is more accurate than the weld count in the LOCA frequency report (7) in any cases where there are deviations (see Section Page 83 of 260 South Texas Project Risk-Informed GSI-191 Evaluation Volume 3: CASA Grande Analysis RI-GSI191-V03 Revision 1 5.3.2). This is a reasonable assumption since the CAD model includes specific references to the source drawings and is consistent with the component database (9).4. Debris Generation Assumptions
- a. It was assumed that the destruction pressure for Microtherm is identical to the destruction pressure for Min-K. This is a reasonable assumption since the two insulation types are essentially the same (43).b. It was assumed that 100% of the miscellaneous debris (tags, labels, etc.) would fail at the beginning of the event. This is a conservative assumption since the majority of the miscellaneous debris would be outside the ZOI and may not fail at all during the event.c. It was assumed that the quantity of unqualified intumescent coatings is negligible and can be excluded from the analysis.
This is a reasonable assumption since the total transportable quantity is only 2 Ibm (see Section 2.2.11).5. Chemical Effects Assumptions
- a. It was assumed that chemical products would not form before the pool temperature drops below 140 *F. This is a reasonable assumption for the purposes of this evaluation since the solubility limit for aluminum precipitates increases significantly at higher temperatures, and calcium precipitates are not expected to form in large quantities for most of the scenarios evaluated (20). Note that the temperature profiles used in the CASA Grande evaluation conservatively minimize the temperature and therefore minimize the time that it would take for chemical products to form.6. Debris Transport Assumptions
- a. It was assumed that there would be no significant transport of intact blanket debris. This is a reasonable assumption since the intact blankets are large pieces that would be easily held up on structures and would be too heavy to transport readily in the containment pool (67).b. It was assumed that there would be no debris washed down from upper containment for an SBLOCA. This is a reasonable assumption since the containment sprays are not initiated for an SBLOCA. This assumption also applies for medium or large breaks where the sprays are not initiated due to a failure of all CS pumps.c. It was assumed that miscellaneous tags, labels, etc. are all located in lower containment and would fall directly in the containment pool. It was also assumed that all of the miscellaneous debris would transport to the strainers at the start of recirculation.
This is a conservative assumption since some of the miscellaneous debris would be in locations above the pool where it would not transport.
Also, based on previous testing, miscellaneous debris would not be likely to transport in the recirculation pool (52).d. It was assumed that all latent debris is on the containment floor at the beginning of the event. This assumption results in an increased transport fraction to inactive cavities, but neglects any retention of latent debris above the pool where much of it could be shielded from containment sprays.Page 84 of 260 South Texas Project Risk-Informed GSI-191 Evaluation Volume 3: CASA Grande Analysis RI-GSI191-V03 Revision 1 e. It was assumed that debris washed down from upper containment reaches the pool after the inactive and sump cavities are filled, but before recirculation is initiated.
This is a conservative assumption since it neglects transport of any washdown debris to inactive cavities during pool fill, but accelerates the time that debris would reach the strainer during the recirculation phase.f. It was assumed that unqualified coatings in upper containment would wash down to the pool immediately after failure if sprays are still on at the time of failure. This is a conservative assumption since it accelerates the time that debris would reach the strainer.g. It was assumed that the debris accumulation on each of the active strainers is proportional to the flow rate through each strainer divided by the total flow rate through all of the strainers.
This is a reasonable assumption since the debris transports with the flow.h. It was assumed that the fine debris that is initially in the pool at the start of recirculation as well as the fine debris that transports to the pool during recirculation would be uniformly distributed in the pool. This is a reasonable assumption since the fine debris in lower containment prior to the start of recirculation would be well mixed in the pool as it fills, and the fine debris washed down from upper containment during recirculation would be well mixed due to the dispersed locations where containment sprays enter the pool.It was assumed that debris generated due to erosion by containment sprays would be transported to the pool prior to the start of recirculation.
This is a conservative assumption since it accelerates the time that debris would reach the strainers.
- 7. Head Loss Assumptions
- a. It was assumed that miscellaneous debris would partially overlap and would fully block strainer flow over an area equivalent to 75% of the miscellaneous debris surface area.This assumption is consistent with the guidance in NEI 04-07 (44).b. It was assumed that small and large pieces of fiberglass debris can be treated as 0.5 inch thick cubes and 1 inch thick cubes respectively to calculate the surface to volume ratio.This is a conservative assumption since small pieces range in size up to six inches and large pieces are greater than six inches.c. It was assumed that all coatings materials would have a packing fraction similar to acrylic coatings.
It was also assumed that non-coatings particulate debris would have a packing fraction similar to iron oxide sludge. These assumptions are based on engineering judgment due to limited data.d. It was assumed that a fiber bed of at least 1/1 6 th of an inch is necessary to capture chemical precipitates.
This is a reasonable assumption since a thinner debris bed would not fully cover the strainer and would not support appreciable head losses due to chemical debris.e. It was assumed that 100% of the transported particulate debris would be captured on the strainer at the time of arrival. This assumption does not imply that no particulate Page 85 of 260 South Texas Project Risk-Informed GSI-191 Evaluation Volume 3: CASA Grande Analysis RI-GSI191-V03 Revision 1 would penetrate the strainer.
However, since the in-vessel effects acceptance criteria that were implemented in CASA are independent of the particulate quantity, this assumption is conservative.
- f. It was assumed that the debris on the strainers would be homogenously mixed. This is a reasonable assumption since much of the debris would arrive at the strainer simultaneously.
- 8. Degasification Assumptions
- a. It was assumed that Henry's Law is applicable for degasification calculations.
Henry's Law essentially states that the solubility of a gas in a liquid is proportional to the partial pressure of the gas above the liquid. At the equilibrium saturation level, the number of gas molecules moving into and out of solution is constant.
The initial saturation of gas in the containment pool would have sufficient time to reach equilibrium.
Due to the short time that it would take for flow to pass through the debris bed on the ECCS strainers, there may not be sufficient time to reach equilibrium and all of the gas to come out of solution in the debris bed itself. However, it is expected that equilibrium conditions would be reached downstream of the strainer.
Therefore, Henry's law is considered to be applicable for calculating the air released.b. It was assumed that the pressure drop across an ECCS strainer is an isothermal process.This is a reasonable assumption since the water temperature would not change significantly as the water flows through the strainer.c. It was assumed that the air in containment would be essentially the same as atmospheric air. For example, the addition of nitrogen from the accumulators and the formation of hydrogen due to chemical reactions in the containment pool were not considered.
These and other sources of non-condensable gasses in containment are likely minor compared to the total initial free volume of air in containment.
- d. It was assumed that air behaves as an ideal gas. This is a reasonable assumption since the correction factor for non-ideal behavior at low pressures is essentially negligible (68). For example, the z-factor for air at 5 bar (72.5 psi) and 350 K (170 °F) is 1.0002 (69).e. It was assumed that the relative humidity of the containment atmosphere is 100%'°.This is a reasonable assumption given the amount of steam released into containment during a LOCA.f. It was assumed that the relative humidity of the gas voids downstream of the ECCS strainers is 100%. This is a reasonable assumption since the gas bubbles that are formed would be fully surrounded by water. Note also that this assumption is conservative since maximizing the humidity downstream of the strainer minimizes the partial pressure of the air, and therefore reduces the equilibrium concentration of dissolved air downstream of the strainer.10 Note that a lower relative humidity in containment would increase the concentration of dissolved air in the containment pool, resulting in a larger quantity of air released.Page 86 of 260 South Texas Project Risk-Informed GSI-191 Evaluation Volume 3: CASA Grande Analysis RI-GSI191-V03 Revision 1 g. It was assumed that the average submergence depth (from the surface of the pool to the center of the strainer) can be used for the hydrostatic head. This is a reasonable assumption since the STP strainers are designed for uniform flow distribution.
- h. It was assumed that any gas voids caused by degasification would be transported to the ECCS pumps. This is a conservative assumption since it maximizes potential pump failures due to air ingestion, and also maximizes the NPSH required.It was assumed that the gas void fraction at each pump would be proportional to the pump flow split. This is a reasonable assumption since the flow through the sump suction lines would have to be well mixed bubbly flow to transport the bubbles through the vertical portion of the sump and piping.j. Within this version of the analysis, the void fraction at the pumps was assumed to be the same as the void fraction downstream of the sump strainers.
This is a conservative assumption since it neglects the flow split to the operating pumps as well as the decreased bubble size due to the higher static pressure.9. Penetration Assumptions
- a. It was assumed that the debris beds on the strainers would not be disrupted after the debris initially accumulates.
This is a reasonable assumption since the strainers are not located in the immediate vicinity of any potential breaks.b. It was assumed that debris that penetrates the strainers would be uniformly distributed in the flow and would transport proportional to the flow split to the SI pumps vs. CS pumps (Y) and the flow split to the core vs. bypass paths (A). This is a reasonable assumption since the fiber that penetrates the strainer would be very fine and would easily transport with the flow.c. It was assumed that all debris that penetrates the strainer and transports through the core would be trapped on the core (i.e. 100% filtration efficiency).
This is a conservative assumption since it maximizes the debris load on the core.d. It was assumed that all debris that penetrates the strainer and bypasses the core (either through the containment sprays or directly out the break) would immediately be transported back to the containment pool. This is a conservative assumption since it neglects potential hold-up of debris in various locations and neglects the time that it would take for debris to transport through the systems and wash back to the pool.10. Core Blockage Assumptions
- a. It was assumed that a debris bed would not form at the top of the core (blocking flow to the core) for a hot leg break during the hot leg injection phase. This is a reasonable assumption since the majority of debris penetration would generally occur during the cold leg injection phase. Although it is possible that debris may continue to penetrate the strainer and reach the core even after switchover to hot leg injection, if a debris bed formed and blocked coolant from reaching the core, the water in the core would begin to boil. The boiling and counter-current flow would disrupt the debris bed and allow the SI flow to reach the core. Also, since one train of SI is always left on cold leg injection, it would be necessary for both the top and bottom of the core to be fully blocked by Page 87 of 260 South Texas Project Risk-Informed GSI-191 Evaluation Volume 3: CASA Grande Analysis RI-GSI191-V03 Revision 1 debris for core damage to occur during the hot leg injection phase. This is not considered to be a plausible scenario since the cross flow would prevent a debris bed from forming on either one side or the other.b. It was assumed that a debris bed would not form at the top of the core (blocking flow to the core) for a cold leg break during the hot leg injection phase. Similar to the previous assumption, limited debris penetration later in the event and countercurrent flow due to the buoyancy of the hot water in the core would break up any debris bed that starts to form on the top of the core.c. To calculate the boil-off flow rate for a cold leg break during cold leg injection, it was assumed that the RCS pressure is 14.7 psia, and the SI flow entering the reactor vessel is saturated liquid (i.e. 212 "F). This assumption conservatively maximizes the boil-off flow rate since a lower inlet temperature and/or a higher RCS pressure would increase the enthalpy required to boil the water.11. Boron Precipitation Assumptions
- a. It was assumed that the current STP design basis evaluation methodology used to calculate the required hot leg switchover timing is appropriate with the exception of GSI-191 related phenomenon (i.e. formation of a debris bed on the core). This is an appropriate assumption since the generic boron precipitation issues not related to GSI-191 are being separately addressed by the PWROG.b. It was assumed that for a medium or large cold leg break during cold leg injection, a fiber debris load of at least 7.5 g/FA would form a debris bed that would prevent the natural mixing processes credited in the design basis hot leg switchover calculation resulting in boron precipitation prior to switchover.
This is a conservative assumption since a debris bed of 15 g/FA was necessary to capture chemical precipitates and cause significant blockage concerns.c. It was assumed that boron precipitation would not be an issue for small breaks. This is a reasonable assumption since natural circulation would maintain a relatively steady concentration of boron in the core.d. It was assumed that boron precipitation would not be an issue for medium and large hot leg breaks. This is a reasonable assumption since at least one train would be injecting in the cold leg throughout the event. This flow would pass through the core and maintain a relatively steady concentration of boron. Even if significant core blockage occurs, some flow would still pass through the debris bed and flush through the core.12. Acceptance Criteria Assumptions
- a. It was assumed that failure of one pump in any train due to loss of NPSH margin is equivalent to the failure of all pumps in all trains. This is a conservative assumption since the NPSH margin is not the same for all pumps, and if one pump failed, the sump flow rate would be reduced making it less likely that a second pump would fail. Also, since the trains are independent, failure of one train would not affect the other trains except that suspended debris in the pool after the failure would only accumulate on the remaining trains that are still active.Page 88 of 260 South Texas Project Risk-Informed GSI-191 Evaluation Volume 3: CASA Grande Analysis RI-GSI191-V03 Revision 1 b. It was assumed that structural failure of one strainer would allow sufficient debris ingestion to result in complete failure of the ECCS. This is a conservative assumption since it is possible that the ECCS could continue to operate even with large quantities of debris ingested.c. It was assumed that failure of one pump in any train due to excess air ingestion is equivalent to the failure of all pumps in all trains. This is a conservative assumption since one train or one pump in a given train may ingest significantly more air than the other trains or pumps resulting in the failure of only one train or pump.Page 89 of 260 South Texas Project Risk-Informed GSI-191 Evaluation Volume 3: CASA Grande Analysis RI-GSI191-V03 Revision 1 4 Methodology The methodology for performing a deterministic GSI-191 evaluation is provided in NEI 04-07 Volume 1 (43) as approved by the NRC in their safety evaluation documented in NEI 04-07 Volume 2 (44).Due to numerous uncertainties associated with the analysis and plant-specific conditions, a deterministic approach for addressing GSI-191 by necessity includes significant conservatisms in almost every aspect of the analysis.
Insulation debris quantities are calculated based on the maximum possible break size at the worst case break location.
Debris transport is calculated based on maximum flow rates, minimum water level, and smallest debris size distributions.
Chemical precipitation is calculated based on maximum pool temperature and pH, maximum pool volume, maximum debris quantities, and maximum spray duration.
Strainer head loss is calculated based on maximum quantities of debris generated and transported, minimum debris penetration, maximum flow rate, and minimum pool temperature.
The maximum strainer head loss is compared against the minimum NPSH margin, which is calculated based on maximum flow rate and maximum pool temperature.
Core head loss is calculated based on maximum debris penetration, maximum flow rate, and worst case flow configurations.
The core head loss is also compared to conservative acceptance criteria based on the minimum available driving head.Although the deterministic methodology is relatively well defined, the conservatism in the overall result is compounded by the numerous conservatisms introduced in each portion of the analysis.
Also, as identified above, several conservatisms are mutually exclusive, such as the use of a minimum water level for debris transport and a maximum pool volume for chemical precipitation, or use of a minimum temperature for strainer head loss and a maximum temperature for strainer NPSH margin.In each area of a deterministic analysis, it is permissible to implement analytical refinements to reduce the level of conservatism.
The appendices to NEI 04-07 Volume 2 contain several refinement options such as CFD modeling to reduce debris transport in the containment pool (44). However, every refinement that is applied must be justified to show that some level of conservatism is maintained, and the analysis still provides bounding results.For a risk-informed analysis of GSI-191, it is necessary to postulate all possible events that require recirculation through the ECCS strainers.
To calculate the probability associated with core damage or a subsequent large early release, it is necessary to estimate the frequency of the various initiating events, and determine the outcome for a representative sample of the events (this may require analysis of thousands of different scenarios).
Rather than analyzing these scenarios in a conservative and bounding manner like the deterministic approach, it is necessary to perform the analysis using realistic inputs, methods, and acceptance criteria.Page 90 of 260 South Texas Project Risk-Informed GSI-191 Evaluation Volume 3: CASA Grande Analysis RI-GS1191-V03 Revision 1 For some input variables, a best-estimate value may be adequate for a realistic analysis (this could be true for parameters that have a tight range between the minimum and maximum values or for parameters where the results of the analysis are relatively insensitive to large variations in the parameter values). However, some input variables may require probability distributions.
Figure 4.1 shows an example probability distribution for water volume. Depending on the specific analysis, either the calculated minimum or calculated maximum water volume would be used as an input for a deterministic evaluation." For a risk-informed evaluation, the input probability distribution can be sampled to determine the actual impact on the results with an appropriate probability weight carried through the analysis for the extreme conditions associated with the minimum and maximum values.Best-etnmate fr-o 2 a.Calculated minimum Actual.. minimum Calculated Actual maximum maximum (conservative)
WaterVolume Figure 4.1 -Example of realistic probability distribution for an input variable In addition to using realistic inputs, it is also important to perform a time-dependent evaluation to capture the time-dependent factors and events that are significant to GSI-191. This includes time-dependent failure for unqualified coatings, time-dependent transport of debris to the strainers, time-dependent corrosion and subsequent precipitation of chemical products, time-dependent operator actions such as securing pumps or switching over to hot leg injection, etc.For a risk-informed evaluation, the uncertainties associated with the various input parameters and models must also be estimated and carried through the evaluation.
"1 Note that a deterministic refinement could be applied by reducing the level of conservatism in the minimum or maximum water volume calculation.
This may provide significant improvement, but using a bounding value for the water volume input still produces results that are unrealistically biased in the conservative direction.
Page 91 of 260 South Texas Project Risk-Informed GSI-191 Evaluation Volume 3: CASA Grande Analysis RI-GSI191-V03 Revision 1 The output from CASA Grande is used to feed directly into the plant-specific PRA. The PRA results are then compared to a hypothetically perfect plant configuration with respect to ECCS performance to calculate the change in core damage frequency (CDF) and large early release frequency (LERF). If the ACDF and ALERF values are within Region 3 as defined in Regulatory Guide 1.174 (70), the risk associated with GSI-191 is considered very small. If the ACDF and ALERF values are within Region 2 or Region 1, the risk is more significant, and would require more extensive compensating measures to reduce the risk.Figure 4.2 provides a simplified high level picture of the risk-informed GSI-191 resolution process.Page 92 of 260 South Texas Project Risk-Informed GSI-191 Evaluation Volume 3: CASA Grande Analysis RI-GSI191-V03 Revision 1 Risk-informed Method Realistic/probabilistic" Inputs" Methods" Acceptance Criteria Containment CAD LOCA Frequencies Model/Input Development Model Frequency estimates Perform testing or analysis Detailed model of for break sizes from to develop realistic inputs, insulation, structures Y2" to DEGB at all physical models, and and break locations potential locations acceptance criteria~Uncertainty CASA Grande Quantification Determine uncertainty Analyze debris generation, debris bands for various transport, strainer head loss, air intrusion, parameters and models debris penetration, core blockage, and boron precipitation for thousands of individual accident sequences in a time-dependent manner while representatively sampling variations in each input parameter and propagating uncertainties.
Compare each sequence to appropriate acceptance criteria and summarize results as a failure probability for S/M/L LOCA categories.
Repeat analysis for each possible equipment configuration.
PRA Perform plant Calculate ACDF and ALERF for Within No modifications current configuration vs. RG 1.174 optimized for hypothetically perfect configuration with respect to CDF reduction ECCS performance GSI-191 Resolvedi Figure 4.2 -Risk-informed GSI-191 resolution path Page 93 of 260 South Texas Project Risk-Informed GSI-191 Evaluation Volume 3: CASA Grande Analysis RI-GSI191-V03 Revision 1 4.1 GSI-191 Analysis Steps The risk-informed analysis of the physical phenomena associated with GSI-191 includes the following general steps: 1. Identify the scenarios that must be evaluated.
This includes essentially all events that lead to ECCS sump recirculation from a primary or secondary side break during any mode of operation.
This also includes different equipment failure combinations consistent with the PRA.2. Develop a detailed containment building CAD model. The model should include concrete structures, grating, insulation on equipment and piping, and potential break locations on welds.3. Estimate the frequency of the initiating events. This requires an assessment of the frequency associated with breaks ranging from a 1/2A-inch hole to a full DEGB at each potential break location, based on the following steps: a. Determine the relative probability of breaks in each weld category based on specific degradation mechanisms.
- b. Identify appropriate weld category for each weld location.c. Statistically fit the NUREG-1829 LOCA frequency data.d. Sample the epistemic uncertainty in the NUREG-1829 frequencies using the statistical fit.e. Distribute the sampled total LOCA frequency across all welds based on the relative probabilities.
- f. Sample a variety of break sizes at each weld location and record the appropriate frequency for each sampled break.4. Determine the type, quantity, and characteristics of debris that is generated.
This includes the following steps: a. Determine the appropriate ZOI size for each material based on the destruction pressure and break size.b. Determine the appropriate size distribution for each type of insulation debris based on the insulation type and distance from the break location.c. Calculate the quantity of each type and size of insulation debris based on the ZOI size, insulation location, and break location.d. Calculate the quantity of each type of qualified coatings debris based on the ZOI size, break location, and coatings location.e. Determine the quantity of unqualified coatings debris based on plant walkdowns and logs. Also determine the timing for the coatings failure.f. Determine the quantity of latent debris based on plant walkdowns.
- g. Determine the quantity of miscellaneous debris based on plant walkdowns.
- h. Define the debris characteristics (size and density) for each type of debris.Page 94 of 260 South Texas Project Risk-Informed GSI-191 Evaluation Volume 3: CASA Grande Analysis RI-GSI191-V03 Revision 1 5. Determine the type, quantity, form, and timing of chemical precipitation.
This includes the following steps: a. Calculate the concentration of chemical ions in solution based on pool pH and temperature, material quantities, and corrosion and dissolution rates.b. Determine material solubility limits based on the potential types of precipitates that could form and thermodynamic modeling.c. Calculate the quantity of each type of precipitate and determine the form (amorphous or crystalline) based on the ion concentration and precipitate solubility limits.6. Analyze debris transport during each phase of the event. This includes the following steps: a. Evaluate potential blockage upstream of the strainer.b. Calculate debris transport during the blowdown phase based on the type and size of debris generated inside the ZOI, the break location, and the grating locations.
- c. Calculate debris transport during the washdown phase based on the type and size of debris in upper containment, the spray distribution, and the grating locations.
- d. Calculate debris transport during the pool fill-up phase based on the type and size of debris in lower containment at the end of the blowdown phase, the break and spray flow rate, the cavity volumes below the containment floor elevation, and the pool volume at the time when the cavities would be filled.e. Calculate debris transport during the recirculation phase based on the type and size of debris in the pool, the initial debris distribution at the beginning of recirculation, the pool water level, and the break, spray, and sump flow rates.f. Determine debris erosion fractions based on the type, size, and location of non-transporting pieces of debris.g. Calculate total debris transport to the strainers for each type and size of debris based on the transport fractions for blowdown, washdown, pool fill, recirculation, and erosion.h. Determine the time-dependent arrival of debris at the strainers based on time-dependent failure and transport considerations.
- 7. Determine overall head loss at the strainer and compare to the NPSH and structural margin. This includes the following steps: a. Calculate the CSHL based on the flow rate and temperature.
- b. Calculate the conventional head loss due to fiber and particulate debris based on the flow rate and temperature.
- c. Determine the incremental head loss due to chemical precipitates based on the conventional debris head loss, and the type, form, and quantity of precipitates.
- d. Calculate the total head loss at the strainer based on the CSHL and debris bed head loss.e. Determine the strainer NPSH margin based on the pool temperature, flow rate, and gas void fraction, and compare results to the total strainer head loss.f. Compare the strainer structural margin to the total strainer head loss.8. Analyze air intrusion at the strainer.
This includes the following steps: a. Determine the potential for vortex formation.
Page 95 of 260 South Texas Project Risk-Informed GSI-191 Evaluation Volume 3: CASA Grande Analysis RI-GSI191-V03 Revision 1 b. Calculate the quantity of degasification at the strainer based on the containment pressure, strainer submergence, strainer head loss, flow rate, and temperature.
- c. Determine whether gas would transport through the strainer modules and ECCS suction piping to the pumps.d. Determine the impact of gas voids on the ECCS and CSS pumps.9. Determine the time-dependent quantity of debris that penetrates the strainer.
This includes the following steps: a. Calculate debris penetration based on the flow rate, clean strainer area, and time-dependent arrival of debris at the strainer.b. Define the characteristics for the debris that penetrates the strainer.10. Evaluate ex-vessel downstream effects issues. This includes the following steps: a. Evaluate wear on pumps, valves, and other components from the penetrated debris.b. Evaluate potential clogging of small orifices from the penetrated debris.11. Evaluate in-vessel downstream effects issues. This includes the following steps: a. Analyze heat transfer issues associated with deposition of debris on the fuel rods.b. Identify cases where full blockage at the bottom of the core during cold leg injection would not lead to core damage.c. For cases where blockage at the bottom of the core could lead to core damage, calculate time-dependent transport of debris to the core based on time-dependent penetration, SI and CS pump flow split, and core bypass flow split.d. Determine core blockage acceptance criteria based on driving head and fuel blockage test results.12. Boron precipitation
- a. Identify cases where a debris bed could accelerate the onset of boron precipitation prior to hot leg injection.
- b. Determine boron precipitation acceptance criteria based on debris load necessary to block natural mixing processes.
- 13. Parametric evaluations
- a. Modify input parameter(s) of interest.b. Rerun CASA Grande and compare results to base case to determine influence of parameter(s).
4.2 Structured
Information Process Flow The basic event for a LOCA scenario consists of a single accident progression that is initiated by a broken pipe and continues for 30 days. The following outline provides a high level description of the process flow for evaluating independent LOCA scenarios.
Unlike predictive physics models (like RELAP), which enumerate field equations and constitutive relationships, CASA Grande embodies only mass conservation in the form of a first-order rate equation to track debris fractions in the containment pool.Energy balance is addressed in principle by external calculations (e.g., the pool temperature profiles Page 96 of 260 South Texas Project Risk-Informed GSI-191 Evaluation Volume 3: CASA Grande Analysis RI-GSI191-V03 Revision 1 developed from the thermal-hydraulic modeling).
In this respect, CASA Grande is primarily an uncertainty propagation tool, but the timeline of the accident progression is determined by tracking debris through the system circulation history. The timeline supports externally calculated parameters such as decay heat, pool temperature, operational configurations, chemical product formation, and coatings degradation.
It also provides a basis for comparison to time-dependent performance metrics like NPSH available, and core debris loading relative to the timing for switchover to hot leg injection.
- 1. Set plant failure state (number of trains and specific pumps available).
The failure state determines available flow rates through each train and guides operator actions via EOP.2. Randomly select a weld type/case based on relative frequency of break occurrence.
The relative frequencies reflect susceptibility to failure.3. Randomly select a specific weld from this type/case assuming equal probability among all welds of the same type/case.
The weld location defines P(x,y,z), whether it is a hot leg or cold leg break condition, and the specific compartment in containment.
Each weld location has a pre-defined list of insulation targets that can be "seen" in every direction.
Concrete walls are the only feature that is credited for shielding insulation from potential damage since pipes and large equipment are assumed to have no effect on a ZOI.4. Conditional upon having a break for this specific weld type/case, sample a break diameter that is consistent with NUREG-1829:
Dbreak FDbreaklweld case Equation 18 Record break contribution to SBLOCA, MBLOCA, or LBLOCA category.
The designation of SBLOCA, MBLOCA, or LBLOCA becomes an explicit correlation for many following physical variables.
- 5. Randomly select a complete temperature history T(t) from appropriate correlations of thermal-hydraulic trends for SBLOCA, MBLOCA, or LBLOCA events..6. Calculate radii Rijk of the three damage zones indexed by i = 1,2,3, debris sizes (fines, small pieces, large pieces, or intact blankets) indexed by] = 1,2,3,4, and target type indexed by k, where k E K indexes insulation products in containment.
The three sets are indexed by k: K denotes insulation products, T denotes fiber-based insulation, and £ denotes all types of debris including insulation and other debris such as unqualified coatings and crud particulate; so, F c K c £L. The Rijk damage zones for Nukon are scaled to the maximum damage radius for insulation
- k. Figure 4.2.1 is an illustration that shows the nomenclature of damage for a hypothetical break that has its damage radii truncated by a wall.Page 97 of 260 South Texas Project Risk-Informed GSI-191 Evaluation Volume 3: CASA Grande Analysis RI-GSI191-V03 Revision 1 Figure 4.2.1 -Illustration of a hypothetical DEGB spherical ZOI truncated by a wall 7. If Dbreok < Dpipe, choose a random direction perpendicular to the pipe according to 0 -U(0,27f).Else, q5 is assigned a flag that indicates a spherical ZOI.8. Calculate intersection of damage zones with insulation targets and clip by concrete walls to obtain the amount of debris in each damage radius and debris size (i,],k), and convert volume to mass:=Qk-" Pk I (1Vdna~qe (4) n V~sik.ation)
\ k~met Equation 19 Here, the "\Woocrete" designates exclusion of those insulation targets not damaged due to structural concrete blocking the break jet.Page 98 of 260 South Texas Project Risk-Informed GSI-191 Evaluation Volume 3: CASA Grande Analysis RI-GSI191-V03 Revision 1 9. Apply transport logic to obtain all ZOI-generated debris mass arrival at the pool as a function of break size and compartment location.
Complex transport logic is represented here via the operator Ftronsport:
mPn(0) = Ftransport 0 M Equation 20 The transport logic captures things like erosion of fibers from large pieces to fines in transforming the vector M of Mijk to the vector int(t) of mjk (t) t = 0.10. Introduce fixed quantities of non-ZOI debris types (those in £ but not K and not addressed above) like crud particulate, latent debris, and unqualified coatings debris.11. Apply fill up transport fraction F , to train e's strainer sump cavity. This mass of debris is initially resident on each strainer, in addition to all other debris constituents that arrive over time: Jk(O) = F/llmi ,k (0) Equation 21 12. At each time t, assume homogenous mixing in the pool: C, i,J,k(O)/V(t)
Equation 22 While this form is never used explicitly, it is helpful to think about debris mixing, transport, and accumulation in terms of concentration.
- 13. Solve coupled differential equations for mass in the pool, mass on the strainer, and mass on the core (see Figure 4.2.2 and Figure 4.2.3 for the nomenclature setting): d d t d re(t) ,VkEL Mk(t) = Sk(t) -+mk(t)*e=A,B,C kET drn(t) =f( mL (t) (Q--t) mi (t) -r/vmn/ (t), Vk E L Equation 23 wd Zk (t =v I )(ý-(t)) k k dmcore(t)
= 'em1(t), Vk E F e=A,B,C Page 99 of 260 South Texas Project Risk-Informed GSI-191 Evaluation Volume 3: CASA Grande Analysis RI-GS1191-V03 Revision 1 where sources Sk(t) of debris type k can be time-dependent, flow split X is the fraction of ECCS injection that passes through the fuel, and flow split y is the fraction of total strainer flow that is injected.
The complement (1 -V) is the fraction of total strainer flow passed to containment spray, and the complement (1 -X) is the fraction of ECCS injection that bypasses the core. For cold leg breaks, X is determined based on the time-dependent boil-off rate. For hot leg breaks, A= 1. For simplicity in writing the equations here, the additional subscripts are suppressed and the masses are indexed by debris type k E L. That said, the other indices matter in implementation.
For example, the last term in Equation 23 is only present when the k index indicates fiber, but it is also only present when the size index indicates fines.Figure 4.2.2 -Illustration of the processes local to the ECCS screen Page 100 of 260 South Texas Project Risk-Informed GSI-191 Evaluation Volume 3: CASA Grande Analysis RI-GSI191-V03 Revision 1-L m w-.Figure 4.2.3 -Illustration of the flow paths in the reactor vessel 14. Given histories of fiber and particulate debris thickness 6(t) on the strainer, compute time-dependent head loss across each strainer according to: APe(t) = H (mIn(t), Qe(t)) N(S,1)4 cD,(t)Equation 24 where the function H is given by NUREG/CR-6224 with arguments given by the vector me(t) of mf$(t) for all k E £, and velocity via the flow rate Qt(t), where N(5,1) is a truncated random variable with a mean of 5 and unit variance, and where ch (t) = H 1, 6 (t) < 1/16" or T(t) > N(140,5)1E, otherwise Equation 25 Here, the chemical head loss Dch takes a value of 1 if the thickness is below 1/1 6 th of an inch or the temperature exceeds the specified normal random variable, centered on 140 *F. Otherwise, 0ch takes the value of a shifted, and truncated, exponential random variable, which is denoted by E.15. Compare time-dependent head loss to time-dependent NPSH margin and record the scenario as a failure if: Page 101 of 260 South Texas Project Risk-Informed GSI-191 Evaluation Volume 3: CASA Grande Analysis RI-GSI191-V03 Revision 1 max[AP'(t)
-NPSHmargin(t)]
> 0 Equation 26 t'?In other words, a failure is recorded for this scenario if anywhere along the 30-day time history the head loss exceeds the NPSH margin for any strainer e = A, B, C. The strainer head loss and NPSH margin and other sump failure criteria are illustrated in Figure 4.2.4.Sump Pool Free Surface, Pc Falue ls ocus f l~wPressure drop through the debris bed is compensated
- 2 exceeds the mechanical by the water column down z om= z losses (FL) and less vapor Z pressure (VP)Safety injection pumps bh t o n n, (two in a train) are located below the sump Pumps are operable so long as: to ensure adequate NPSH avail Abed ! NPSH margin Figure 4.2.4 -Illustration of sump failure criteria 16. Compare time-dependent head loss to the strainer structural margin and record the scenario as a failure if: maxAPe(t)
> APmech Equation 27 t,e where APmech is the design strainer structural strength in terms of pressure drop across the strainer.Page 102 of 260 South Texas Project Risk-Informed GSI-191 Evaluation Volume 3: CASA Grande Analysis RI-GS1191-V03 Revision 1 17. Given time-dependent head loss, calculate time-dependent gas evolution and record the scenario as a failure if: max Fvoid (APe (t)) > 2%t,e Equation 28 18. For cold leg breaks, compare the time-dependent fiber accumulation on the core against the assumed 7.5 g/FA threshold.
Record the scenario as a failure if maxt mcore(t) > 7.5g/FA.19. For hot leg breaks, record the scenario as a success in terms of the core blockage and boron precipitation criteria.20. If any performance threshold is exceeded for the scenario, then record a failure.Figure 4.2.5 is an illustration of the processes listed above that need to be evaluated in GSI-191 for ECCS performance during the recirculation phase.ECCS ScreenHole
.(2 PIs)Particulate debris (chemical, other)flittered in the screen increases 0 pressure drop-i 0 0 0/Fiber in the debris bed causes Ipressure7 0 0 4/*Bubblesmsayform
'?'the fractionof the bdbbe voiume.downstrem of the to thetptul volume strainer at higher to h. dow Wnstea pressure drops ows Fiber penetration thvnamh ~er~n Figure 4.2.5 -Illustration of processes local to the strainer with a direct impact on the performance thresholds Page 103 of 260 South Texas Project Risk-Informed GSI-191 Evaluation Volume 3: CASA Grande Analysis RI-GSI191-V03 Revision 1 4.3 Uncertainty Quantification and Propagation As discussed above, the steps listed in Section 4.2 provide a high level illustration of the calculations within CASA Grande for a single scenario.
That specific scenario includes numerous random realizations including the selection of the specific weld location where the break occurs, the effective size of the break, the direction of the break on the pipe, etc. Although it is not always explicitly stated in the Section 4.2 description, many of the steps outlined depend on the specifics of the scenario.
To construct a Monte Carlo estimator of the failure probability, these steps would be replicated many times.However, CASA Grande does not simply construct a so-called na'ive Monte Carlo estimator.
Rather, techniques are used to reduce the variability of the failure probability calculations and to propagate uncertainties (such as the epistemic uncertainty in the initiating frequency) to the PRA, where these failure probabilities become branch fractions at the top event.GSI-191 evaluations include complex calculations with numerous areas of uncertainty.
In some cases, conservative values were selected for input parameters, but in many cases, probability distributions were developed to evaluate the full realistic range of conditions.
The probability distributions for each parameter were sampled and propagated with the appropriate weighting to realistically determine the risk associated with GSI-191 phenomena.
The detailed methodology for uncertainty quantification and propagation is described in a report by UT Austin (71).4.4 Verification and Validation A verification and validation (V&V) process is used to ensure that software fulfills the intended purpose.Verification tests are performed to ensure that the software has been correctly programmed (i.e. it correctly solves the equations that it is intended to solve). Validation tests are performed to ensure that the software correctly models the real physical phenomena (i.e. the equations that are programmed are the correct equations to represent reality).Within this version of the analysis, it was not possible to complete a full V&V of CASA Grande. However, this document provides the basis for the validity of the equations that are used in CASA. This validation is based on extensive testing that has been conducted specifically for STP as well as general industry testing. The verification that the equations were correctly programmed in CASA was performed by comparing a series of hand and alternative software calculations (72).Page 104 of 260 South Texas Project Risk-Informed GSI-191 Evaluation Volume 3: CASA Grande Analysis RI-GSI191-V03 Revision 1 5 Analysis This section describes the physical models used in CASA Grande and the calculations performed to determine debris generation, debris transport, strainer head loss, chemical effects, air intrusion, strainer debris penetration, ex-vessel downstream effects, core blockage, and boron precipitation.
5.1 Evaluation
Scenarios (PRA Branch Fractions to Populate)The STP PRA evaluates LOCA scenarios that fall into the categories of small breaks (up to 2 inches), medium breaks (2 to 6 inches) and large breaks (greater than 6 inches). The PRA also evaluates a variety of equipment failure scenarios and different operating modes. To populate specific PRA branch fractions related to GSI-191 phenomena, it is necessary to evaluate the full range of potential scenarios.
As discussed in Assumption L.a, the CASA Grande evaluation was only performed for full power operation (Mode 1). The full spectrum of break sizes was evaluated and subsequently binned into the small, medium, and large categories.
Potential equipment failures that can affect the GSI-191 analyses include pump failures (either individual pumps or full trains) and fan cooler failures.
The most significant variable affected by the failure of fan coolers is the containment pool temperature.
This is evaluated as part of the thermal-hydraulic analysis (5), but was not explicitly evaluated in CASA Grande. Pump failures, on the other hand, are much more important to the overall GSI-191 analysis, and therefore were directly evaluated by running multiple scenarios with different combinations of pump failures.STP has a configuration of three trains with one sump per train. Each train has 3 pumps, an LHSI pump, an HHSI pump, and a CS pump. The maximum pump flow rates are 2,800 gpm for each of the LHSI pumps, 1,620 gpm for each of the HHSI pumps, and 2,600 gpm for each of the CS pumps (see Section 2.2.9). Variations in the pump flow rates affect several important areas of the overall GSI-191 evaluation, so pump failure scenarios must be carefully evaluated.
The following list provides the primary areas that are impacted by pump flow rates: 1. Washdown Transport:
Washdown transport is a function of the total CS flow rate for all pumps.However, based on the assumptions used in the washdown analysis, the washdown transport fraction is assumed to be constant unless all three CS pumps fail and the total CS flow rate is 0 gpm (in which case negligible washdown would be assumed to occur).2. Recirculation Transport:
Recirculation transport is a function of the total break flow rate (HHSI plus LHSI) and the total CS flow rate. Higher pump flow rates would increase the pool turbulence in the locations where the break and spray flow enters the pool, and would also increase the pool velocities in the approach paths to the strainers.
However, since large pieces of debris would not reach the pool for most scenarios (e.g. breaks inside the SG compartments), and fine debris would transport to the strainers even at relatively low flow rates, flow rate variations on Page 105 of 260 South Texas Project Risk-Informed GSI-191 Evaluation Volume 3: CASA Grande Analysis RI-GSI191-V03 Revision 1 recirculation transport would essentially only affect the transport fraction for small pieces of fiberglass debris.3. Debris Accumulation:
Since fine debris would be transported in suspension, the accumulation on the strainers would be proportional to the flow split (i.e. if one sump has twice as much flow as another sump, the debris load on that sump strainer will be twice as high as the other strainer).
- 4. Approach Velocity:
The approach velocity for each strainer is equal to the sump flow divided by the strainer area for each train.5. Strainer Head Loss: The head loss for each strainer is a function of the quantity of debris on the strainer and the strainer approach velocity.6. Degasification:
The quantity of air released from solution for each sump is a function of the strainer head loss and the flow rate through the strainer for each train.7. Strainer Debris Penetration:
The quantity of fiber debris that penetrates each strainer is a function of the debris quantity that reaches the strainer and the flow rate through the strainer.8. Reactor Vessel Debris Quantity:
The quantity of fiber debris that reaches the reactor vessel is a function of the strainer debris penetration and the flow split between the CS pumps and the SI pumps for each train.9. Core Accumulation:
The quantity of debris that accumulates in the core for a cold leg break during cold leg injection is a function of the boil-off makeup flow rate compared to the total SI flow rate.These effects are discussed in more detail in the following sections.
Any combination of pumps could fail due to mechanical problems, giving a total of 512 possible permutations for the STP configuration.
However, the number of cases that need to be analyzed can be reduced if certain assumptions are made. By applying Assumption 2.a (failures in one train are indistinguishable from failures in another train) and Assumption 2.b (combination of pump failures in one train is worse than the same combination of pump failures in separate trains), the total number of pump combination states can be reduced to 64. The frequency for each of these pump combination states is provided in Section 2.2.4.Since the pump combination states with a frequency less than 2E-09 would have a negligible impact on the overall CDF and LERF, these cases can be conservatively assumed to all go to failure without significantly affecting the overall results (see Assumption 2.f). This eliminates 48 low frequency pump combination states. Table 5.1.1 shows the sixteen pump combination states that have a frequency higher than 2E-09.By applying Assumption 2.c (bounding strainer debris accumulation and approach velocity) and Assumption 2.d (bounding core accumulation), the total number of cases can be reduced to five pump combination states that need to be evaluated.
Note that since one CS pump is procedurally secured whenever all three CS pumps are confirmed to be operating (before the start of recirculation), cases with 2 CS pumps operating are essentially identical to cases with all 3 CS pumps operating.
Page 106 of 260 South Texas Project Risk-Informed GSI-191 Evaluation Volume 3: CASA Grande Analysis RI-GS1191-V03 Revision 1 Table 5.1.1 -Bounding or representative cases for highest frequency pump combination states Bounding Bounding Working Working Working Pump Case for Case for Case HHSI LHSI CS State Comments Strainer Vessel Pumps Pumps Pumps Frequency Failure Failure One CS pump 1 3 3 3 2.64E-04 Case 1 Case 1 Ocedure procedurally secured 2 3 3 2 3.32E-06 Case 1 Case 1 Identical to Case 1 3 3 3 1 7.53E-08 Case 22 Case 9 4 3 3 0 9.77E-09 Case 1 Case 9 One CS pump 5 3 2 3 3.49E-06 Case 22 Case 9 Ocedure procedurally secured 6 3 2 2 4.38E-08 Case 22 Case 9 Identical to Case 5 9 3 1 3 3.22E-08 Case 9 Case 9 One CS pump procedurally secured 17 2 3 3 1.94E-06 Case 22 Case 9 One CS pump procedurally secured 18 2 3 2 2.44E-08 Case 22 Case 9 Identical to Case 17 One CS pump 21 2 2 3 1.17E-07 Case 22 Case 22 procedurally secured, Identical to Case 22 22 2 2 2 9.16E-06 Case 22 Case 22 Single train failure 23 2 2 1 7.81 E-08 Case 26 Case 26 26 2 1 2 6.03E-08 Case 26 Case 26 One CS pump 33 1 3 3 2.67E-08 Case 22 Case 9 Ocedure I I procedurally secured 38 1 2 2 3.54E-08 Case 26 Case 26 43 1 1 1 4.34E-08 Case 43 Case 43 Dual train failure The scenarios that were explicitly evaluated in CASA Grande were:* Case 1: Full train operation* Case 22: Single train failure* Case 43: Dual train failure* Case 9: Two LHSI pump failures" Case 26: Single train failure with failure of one additional LHSI pump All other high frequency pump state cases are bounded by these five pump combination states as shown in Table 5.1.1.Page 107 of 260 South Texas Project Risk-Informed GSI-191 Evaluation Volume 3: CASA Grande Analysis RI-GSI191-V03 Revision 1 5.2 Containment CAD Model A CAD model of the STP containment building was developed to perform a variety of GSI-191 calculations as well as to define the geometry in CASA Grande (4). The details included in the CAD model and specific containment features are illustrated in Figure 5.2.1 through Figure 5.2.20.Figure 5.2.1 -Cross-section of steam generator compartment with Loops B and C Page 108 of 260 South Texas Project Risk-Informed GSI-191 Evaluation Volume 3: CASA Grande Analysis RI-GS1191-V03 Revision 1 Figure 5.2.2 -Close-up view of steam generator compartment with Loops B and C Page 109 of 260 South Texas Project Risk-Informed GSI-191 Evaluation Volume 3: CASA Grande Analysis RI-GS1191-V03 Revision 1 Figure 5.2.3 -Operating deck (Elevation 68'-0")Page 110 of 260 South Texas Project Risk-Informed GSI-191 Evaluation Volume 3: CASA Grande Analysis RI-GSI191-V03 Revision 1 Figure 5.2.4 -Piping and equipment (View 1)Page 111 of 260 South Texas Project Risk-Informed GSI-191 Evaluation Volume 3: CASA Grande Analysis RI-GS1191-V03 Revision 1 Figure 5.2.5 -Piping and equipment (View 2)Page 112 of 260 South Texas Project Risk-Informed GSI-191 Evaluation Volume 3: CASA Grande Analysis RI-GS1191-V03 Revision 1 Figure 5.2.6 -Steam generator compartment floor (Elevation 19'0")Page 113 of 260 30-inch vent holes South Texas Project Risk-Informed GSI-191 Evaluation Volume 3: CASA Grande Analysis RI-GSI191-V03 Revision 1 Sump C*Sump B"Sump A Figure 5.2.7 -Plan view of containment floor (Elevation
-11'3")Page 114 of 260 South Texas Project Risk-Informed GSI-191 Evaluation Volume 3: CASA Grande Analysis RI-GSI191-V03 Revision 1 Figure 5.2.8 -Isometric view of containment floor (Elevation
-11'3")Page 115 of 260 South Texas Project Risk-Informed GSI-191 Evaluation Volume 3: CASA Grande Analysis RI-GSI191-V03 Revision 1 Figure 5.2.9 -Plan view of major piping and equipment Page 116 of 260 South Texas Project Risk-Informed GSI-191 Evaluation Volume 3: CASA Grande Analysis RI-GS1191-V03 Revision 1 El 83'-0" -El 68'-" -El 19'-0" ElI(-11)'-3"-
Figure 5.2.10 -Section view of RCS Loop D (left) and Loop A (right)Page 117 of 260 South Texas Project Risk-Informed GSI-191 Evaluation Volume 3: CASA Grande Analysis RI-GS1191-V03 Revision 1 El 98'-6" El 83'-0" El 68'-0" -El 19'-0" -El 5-9" El (-11)'-3" --El (-2)'-0" Figure 5.2.11 -Section view of RCS Loop D (left) and Loop C (right)Page 118 of 260 South Texas Project Risk-Informed GSI-191 Evaluation Volume 3: CASA Grande Analysis RI-GSI191-V03 Revision 1 Figure 5.2.12 -Nukon insulation on piping, pressurizer, pumps, and heat exchangers Page 119 of 260 South Texas Project Risk-Informed GSI-191 Evaluation Volume 3: CASA Grande Analysis RI-GS1191-V03 Revision 1 Figure 5.2.13 -Thermal-Wrap insulation on steam generators Page 120 of 260 South Texas Project Risk-Informed GSI-191 Evaluation Volume 3: CASA Grande Analysis RI-GSI191-V03 Revision 1 Figure 5.2.14 -Microtherm insulation in secondary shield wall penetrations Page 121 of 260 South Texas Project Risk-Informed GSI-191 Evaluation Volume 3: CASA Grande Analysis RI-GSI191-V03 Revision 1 Figure 5.2.15 -Lead blankets on pipes Page 122 of 260 South Texas Project Risk-Informed GSI-191 Evaluation Volume 3: CASA Grande Analysis RI-GSI191-V03 Revision 1 Figure 5.2.16 -Welds representing potential LOCA break locations (View 1)Figure 5.2.17 -Welds representing potential LOCA break locations (View 2)Page 123 of 260 South Texas Project Risk-Informed GSI-191 Evaluation Volume 3: CASA Grande Analysis RI-GSI191-V03 Revision 1 Figure 5.2.18 -Currently installed ECCS strainers Page 124 of 260 South Texas Project Risk-Informed GSI-191 Evaluation Volume 3: CASA Grande Analysis RI-GSI191-V03 Revision 1 m t at Figure 5.2.19 -Illustration of additional insulation modeled at hanger and valve locations Page 125 of 260 South Texas Project Risk-Informed GSI-191 Evaluation Volume 3: CASA Grande Analysis RI-GSI191-V03 Revision 1 PRZ-2-N ,-SE 16RC-1412-NSS 16RC-1412-NSS-6
-16RC-1412-NSS-5
"-16RC-1412-NSS.4 Figure 5.2.20 -Illustration of work points used to identify location of welds, hangers, and valves The geometrical details of the pipes, pipe insulation, and work points (weld, hanger, and valve locations) were exported from the CAD model to a text format. As shown in Figure 5.2.21, the text data includes the part name (which specifies the line number and insulation type if applicable), the coordinates for the junction of each pipe segment, the bend radius for curved portions of the pipe, the inner and outer diameters (either of the pipe or insulation depending on the part), and a text identifier for any work points that are included on the line. The text data was imported into CASA Grande to define the geometry of the piping and associated insulation.
The insulation associated with the equipment (steam generators, pumps, and pressurizer) was defined by creating primitive shapes based on the dimensions of significant features of the equipment defined in the CAD model.The concrete walls and floors were exported from the CAD model and imported into CASA Grande in stereolithography (STL) format to define robust barriers that would protect some insulation from the break jet. The concrete STL file is shown in Figure 5.2.22. As shown in Figure 5.2.23, the grating in the steam generator compartments was also exported from the CAD model to STL format to assist in blowdown debris transport calculations in CASA Grande. However, this refinement has not yet been implemented.
Page 126 of 260 South Texas Project Risk-Informed GSI-191 Evaluation Volume 3: CASA Grande Analysis RI-GSI191-V03 Revision 1 11-09-21 south Texas Plant.iam Number of Points = 3. Number of straights
= 1. unit of Length = Inches..ipt Name,Point,X,Y,Z,Rad,ID,OD,WP 0.75RC-1002-BB2
[NUKON]:1,0,97.81,-594.19,998,0,1.05,5.05, 0.75RC-1002-BB2
[NUKON]:1,1,94.56,-594.19,998,0,1.05,5.05,FW0002 0.75RC-1002-BB2
[NUKON]:1,2,86.06,-594.19,998,0,1.05,5.05,FwOO01 Point to Point Length: 11.75 11-09-21 south Texas Plant.iam Number of Points = 3. Number of straights
= 2. unit of Length = Inches..ipt Name,Point,X,Y,Z,Rad,ID,OD,WP 0.75RC-1006-BB1
[NUKON]:1,0,28.6,-725.86,1199.92,0,1.05,6.05, 0.75Rc-1006-BBI
[NUKON:l1,1,21.71,-720.48,1199.92,0,1.05,6.05, 0.75RC-1006-BB1
[NUKON]:1,2,21.71,-720.48,1209.19,0,1.05,6.05, Point to Point Length: 18.02 11-09-21 south Texas Plant.iam Number of Points = 14. Number of straights
= 11. unit of Length = Inches..ipt Name,Point,X,Y,Z,Rad,ID,OD,WP 0.75RC-1007-BD7
[NUKON]:1,0,2.43,-606,1173.07,0,1.05,6.05, 0.75RC-1007-BD7
[NUKON]:1,1,2.43,-606,1181.82,0,1.05,6.05, 0.75RC-1007-BD7
[NUKON]:1,2,15.83,-616.47,1181.82,0,1.05,6.05, 0.75RC-1007-BD7
[NUKON]:1,3,15.83,-616.47,1199.92,0,1.05,6.05, 0.75RC-1007-BD7
[NUKON]:1,4,83.5,-669.34,1199.92,0,1.05,6.05, 0.75RC-1007-BD7
[NUKONI:1,5,35.27,-731.07,1199.92,0,1.05,6.05, 0.75RC-1007-BD7
[NUKONL:1,6,28.6,-725.86,1199.92,0,1.05,6.05, Point to Point Length: 216.52 0.75RC-1007-BD7
[NUKON]:1,0,53.95,-646.25,1199.92,0,1.05,6.05, 0.75RC-1007-BD7
[NUKON]:1,1,48.71,-652.95,1199.92,0,1.05,6.05, 0.75RC-1007-BD7
[NUKON]:1,2,6.2,-619.73,1199.92,0,1.05,6.05, 0.75RC-1007-BD7
[NUKON]:1,3,0.38,-627.18,1199.92,0,1.05,6.05, Point to Point Length: 71.91 0.75RC-1007-BD7
[NUKONJ:1,0,59.58,-699.94,1199.92,0,1.05,6.05, 0.75RC-1007-BD7
[NUKON]:1,1,46.16,-689.46,1199.92,0,1.05,6.05, 0.75RC-1007-BD7
[NUKON]:1,2,51.55,-682.56,1199.92,0,1.05,6.05, Point to Point Length: 25.78 Figure 5.2.21 -Example of CAD model text data output Page 127 of 260 South Texas Project Risk-Informed GSI-191 Evaluation Volume 3: CASA Grande Analysis RI-GSI191-V03 Revision 1 Figure 5.2.22 -Concrete walls and floors exported from CAD model in STL format Page 128 of 260 South Texas Project Risk-Informed GSI-191 Evaluation Volume 3: CASA Grande Analysis RI-GSI191-V03 Revision 1 Figure 5.2.23 -Grating exported from CAD model in STL format Figure 5.2.24 shows the geometry of the piping and equipment insulation in CASA Grande.Page 129 of 260 South Texas Project Risk-Informed GSI-191 Evaluation Volume 3: CASA Grande Analysis RI-GS1191-V03 Revision 1 Figure 5.2.24 -Geometry of piping and equipment insulation in CASA Grande 5.3 LOCA Frequency Determining the initiating event frequency is a key requirement in performing a risk-informed evaluation.
Estimating the frequencies for LOCA pipe breaks, particularly larger breaks, is challenging since there is limited data from operating experience (due to the very low probabilities of these breaks occurring).
The best generic estimates for LOCA frequencies are based on an expert elicitation process that was documented in NUREG-1829 (37). NUREG-1829 provides LOCA frequencies as a function of break size for both BWR and PWR plants. These values are total frequencies that include all potential primary-side break locations.
However, since two equivalent-size breaks in different locations may have a significantly different likelihood of occurrence as well as a significantly different effect on GSI-191 related phenomena (e.g. quantity of debris generated, transport fractions, in-vessel flow paths, etc.), the total frequencies for all possible break locations must be broken down into the specific frequencies for each break location.
The LOCA frequencies must then be appropriately sampled to evaluate the full range of potential LOCA scenarios.
This was done using the following steps: Page 130 of 260 South Texas Project Risk-Informed GSI-191 Evaluation Volume 3: CASA Grande Analysis RI-GSI191-V03 Revision 1 1. Calculate the relative probability of breaks for specific weld categories based on pipe size, weld type, applicable degradation mechanisms, etc.2. Identify applicable weld category and spatial coordinates for each weld location.3. Statistically fit the NUREG-1829 frequencies (5 1h Median, and 9 5 th) using a bounded Johnson distribution for each size category.
These fits represent the epistemic uncertainty associated with LOCA frequencies.
- 4. Sample epistemic uncertainty (e.g. 6 2 nd percentile) and determine the corresponding total frequency curve based on the bounded Johnson fits (assuming linear interpolation between size categories).
- 5. Distribute total LOCA frequency to each weld location based on the relative probability.
- 6. Sample break sizes at each weld location and proceed with the GSI-191 analysis carrying the appropriate initiating event frequencies.
5.3.1 Relative
Probability of Breaks in Specific Weld Categories As discussed in Section 2.2.3, the relative frequencies of breaks in various weld locations are based on specific degradation mechanisms for categories of welds. These frequencies were determined from an analysis of DM-dependent weld failure rates based on service data, a Bayes method for uncertainty treatment developed in the EPRI risk-informed in-service inspection (RI-ISI) program, and estimates of conditional probability versus break size using information developed in NUREG-1829.
The resulting weld specific LOCA frequencies are used to establish the relative probabilities of break size and location that are subsequently normalized against the NUREG-1829 frequencies.
Descriptions of the 45 unique categories are provided in Table 2.2.3 through Table 2.2.6, and summarized in Table 5.3.1.Note that the pipe size listed in Table 5.3.1 is the nominal diameter, which is treated the same as the inner diameter.
The DEGB size is the diameter of an equivalent hole with twice the inner area of the pipe (i.e. the equivalent break size given a fully offset DEGB with jets emanating from both sides of the broken pipe), and is calculated using the following equation: DDEGB = NF2", Di Equation 29 where: DDEGB:= Equivalent DEGB break size diameter assuming full pipe offset Di = Pipe inner diameter For the hot and cold leg piping, the nominal diameter is equal to the inner diameter.
However, the nominal diameter is larger (and in some cases significantly larger) for the higher schedule/thicker walled pipes that are 16 inches and smaller. For example, the surge line is a 16-inch, Schedule 160 pipe, which Page 131 of 260 South Texas Project Risk-Informed GSI-191 Evaluation Volume 3: CASA Grande Analysis RI-GSI191-V03 Revision 1 has an inner diameter of 12.81 inches. Therefore, the DEGB size would be 18.12 inches rather than 22.63 inches as shown in Table 5.3.1.The weld types include: " ASME Xl Category B-F welds (bimetallic)
- ASME Xl Category B-J welds (single metal)* Branch connection (BC) welds, which are B-J welds used at branch connections The degradation mechanisms include: " Design and construction defects (D&C)* Intergranular stress corrosion cracking (IGSCC)* Transgranular stress corrosion cracking (TGSCC)" Primary water stress corrosion cracking (PWSCC)* Thermal fatigue (TF)* Vibration fatigue (VF)As discussed in Section 5.3.2 and Assumption 3.f, the weld count provided in Section 2.2.3 are not consistent with the CAD model for all break categories.
Therefore, the weld counts were modified slightly in Table 5.3.1 through Table 5.3.5, and the values that were modified are marked with an asterisk.
Also, Category 6B contains two weld sizes (nominal 0.75-inch and 1-inch pipes), and Categories 6A and 8C contain two weld sizes (nominal 1.5-inch and 2-inch). As noted in the tables, the different weld sizes were captured as subcategories.
Table 5.3.1 -Description of weld categories Nominal Actual DEGB Weld Category System Pipe Size Pipe Size DM No. Welds (in) (in)61-1 Small Bore 0.75* 0.614 0.87SC, D&C 613-2 1 1 0.815 1.15 17 7L SIR 1.5 N/A N/A B-J D&C 0 5. Pressurizer 2 1.689 2.38 B-J TF, D&C 2 6A-I 1.5* 1.338 1.89 1 Small Bore -- 1.338 18 B-J VF, SC, D&C 1*6A-2 2 1.689 2.38 23*7K SIR 2 1.689 2.38 BC D&C 11*8A CVCS 2 1.689 2.38 B-J TF, VF, D&C 10 8C-1 1.5* 1.338 1.89 8 CVCS -____-- B-i VF, D&C8 8C-2 ____ 2 1.689 2.38 B-J VF, 39 4D Surge Line 2.5 2.125 3.01 B-J TF, D&C 6 Page 132 of 260 South Texas Project Risk-Informed GSI-191 Evaluation Volume 3: CASA Grande Analysis RI-GSI191-V03 Revision 1 Nominal Actual DEGB Weld Category System Pipe Size Pipe Size (in) Type DM No. Welds (in) (in)5B Pressurizer 3 2.626 3.71 B-J TF, D&C 14 SD Pressurizer 3 2.626 3.71 B-J D&C 4 71 SIR 3 2.626 3.71 BC D&C 8*5C Pressurizer 4 3.438 4.86 B-J D&C 53 51 Pressurizer 4 3.438 4.86 BC D&C 2 71 SIR 4 3.438 4.86 BC D&C 5 8B CVCS 4 3.438 4.86 B-J TF, VF, D&C 19 8D CVCS 4 3.438 4.86 B-J VF, D&C 6 8E CVCS 4 3.438 4.86 BC TF, D&C 4 8F CVCS 4 3.438 4.86 BC D&C 1 5A Pressurizer 6 5.189 7.34 B-J TF, D&C 28*5E Pressurizer 6 5.189 7.34 B-J D&C 29 5F Pressurizer 6 5.189 7.34 B-F SC, TF, D&C 4*5G Pressurizer 6 N/A N/A B-F SC, D&C 0 5H Pressurizer 6 5.189 7.34 B-F D&C (Weld Overlay) 4 7H SIR 6 5.189 7.34 B-J D&C 23 7B SIR 8 6.813 9.64 B-J TF, D&C 9 7C SIR 8 6.813 9.64 B-J I SC, TF, D&C 3 7G SIR 8 6.813 9.64 BC, B-J D&C 42 7F SIR 10 8.500 12.02 B-J D&C 30 7A SIR 12 10.126 14.32 B-J TF, D&C 21 7D SIR 12 10.126 14.32 B-J SC, D&C 3 7E SIR 12 10.126 14.32 BC, B-J D&C 57 7M ACC 12 N/A N/A B-J SC, D&C 0 7N ACC 12 10.126 14.32 B-J TF, D&C 35 70 ACC 12 10.126 14.32 BC, B-J D&C 15 4A Surge Line 16 12.814 18.12 B-F SC, TF, D&C 1 4B Surge Line 16 12.814 18.12 B-J TF, D&C 7 4C Surge Line 16 12.814 18.12 BC TF, D&C 2 3A Cold Leg 27.5 27.500 38.89 B-F SC, D&C 4 3C Cold Leg 27.5 27.500 38.89 B-J D&C 12 1A Hot Leg 29 29.000 41.01 B-F SC, D&C 4 1B Hot Leg 29 29.000 41.01 B-J D&C 11 1C Hot Leg 29 29.000 41.01 B-J TF, D&C 1 2 SG Inlet 29 29.000 41.01 B-F SC, D&C 4 3B Cold Leg 31 31.000 43.84 B-F SC, D&C 4 3D Cold Leg 31 31.000 43.84 B-A D&C 24 Total 786*Page 133 of 260 South Texas Project Risk-Informed GSI-191 Evaluation Volume 3: CASA Grande Analysis RI-GSI191-V03 Revision 1 For the CASA Grande analysis, the frequencies in Table 2.2.3 through Table 2.2.6 were linearly interpolated in 0.1 inch increments.
An example of this process (although not at 0.1 inch increments) is shown in Table 5.3.2 through Table 5.3.5, where the blue text represents interpolated values.Page 134 of 260 South Texas Project Risk-Informed GSI-191 Evaluation Volume 3: CASA Grande Analysis RI-GSI191-V03 Revision 1 Table 5.3.2 -Interpolated relative frequencies vs. break size for hot leg, SG inlet, cold leg, and surge line welds (Categories 1A through 4D)Category 1A 1B iC 2 3A 38 3C 3D 4A 4B 4C 4D No. Welds 4 11 1 4 4 4 12 24 1 7 2 6 DEGS (in) 41.01 41.01 41.01 41.01 38.89 43.84 38.89 43.84 18.12 18.12 18.12 3.01 Break Size, X F(LOCA>X)
F(LOCA>X)
F(LOCA>X)
F(LOCA>X)
F(LOCAX) F(LOCA>X)
F(LOCA>X)
F(LOCA>X)
F(LOCA>X)
F(LOCA.X)
F(LOCA>X)
F(LOCA>X)(in)__________________
0.5 4.02E-07 1.95E-09 1.25E-08 1.98E-06 1.51E-07 1.51E-07 2.79E-09 2.79E-09 9.75E-06 7.44E-08 1.21E-07 7.44E-08 0.9 2.875E-07 1.395E-09 8.937E-09 1.417E-06 1.078E-07 1078E-07 1 992E-09 1.992E-09 7.364E-06 5.620E-08 9.144E-08 5 620E-08 1.0 2.473E-07 1.200E-09 7.685E-09 1220E-06 9.265E-08 9.265E-08 1.712E-09 1.712E-09 6525E-06 4.980E-08 8.105E-08 4 980E-08 1.2 2.008E-07 9.744E-10 6.241E-09 9.914E-07 7.515E-08 7.515E-08 1.388E-09 1.388E-09 5.558E-06 4.242E-08 6.907E-08 4.242E-08 1.5 9.25E-08 4.49E-10 2.87E-09 4.59E-07 3.43E-08 3.43E-08 6.33E-10 6.33E-10 3.30E-06 2.52E-08 4.11E-08 2.52E-08 1.9 7.433E-08 3.609E-10 2.308E-09 3.701E-07 2.611E-08 2 611E-08 4,817E-10 4.817E-10 2,621E-06 1.997E-08 3.260E-08 1.997E-08 2.0 6.92E-08 3.36E-10 2.15E-09 3.45E-07 2.38E-08 2.38E-08 4.39E-10 4.39E-10 2.43E-06 1.85E-08 3.02E-08 1.85E-08 2.4 6.042E-08 2.934E-10 1.876E-09 3.017E-07 2.015E-08 2.015E-08 3.717E-10 3 717E-10 2.107E-06 1.603E 08 2.621E-08 1603E-08 3.0 4.61E-08 2.24E-10 1.43E-09 2.31E-07 1.42E-08 1.42E-08 2.62E-10 2.62E-10 1.58E-06 1.20E-08 1.97E-08 1.20E-08 3.7 3.602E-08 1.750E-10 L.118E-09 1.806E-07 1.086E-08 1.086E-08 2,002E-10 2,002E-10 1.190E-06 9.032E-09 1,480E-08 4.0 3.19E-08 1.55E-10 9.90E-10 1.60E-07 9.49E-09 9.49E-09 1.75E-10 1.75E-10 1.03E-06 7.82E-09 1.28E-08 4.9 2.631E-08 1279E-10 8.176E-10 1.321E-07 7727E-09 7,727E-09 1,425E-10 1.425E-10 8.270E-07 6.289E-09 1.028E-08 5.7 2.111E-08 1.026E-10 6.572E-10 1.062E-07 6,087E 09 6,087E-09 1.123E-10 1.123E-10 6.382E-07 4.865E-09 7.936E-09 6.0 1.89E-08 9.19E-11 5.89E-10 9.52E-08 5.39E-09 5.39E-09 9.95E-11 9.95E-11 5.58E-07 4.26E-09 6.94E-09 6.8 1.61E-08 7.83E-11 5.01E-10 8.12E-08 4.53E-09 4.53E-09 8.36E-11 8.36E-11 4.68E-07 3.57E-09 5.82E-09 7.3 1.536E-08 7.469E-1 1 4.780E-10 7,732E-08 4325E 09 4.325E-09 7 981E-11 7.981E-11 4.395E-07 3.353E-09 5,466E-09 8.5 1,392E-08 6767E-11 4.331E-10 6.9751-08 3.925E-09 3.925E-09 7.242E-11 7.242E-11 3,840E-07 2.930E-09 4.776E-09 9.6 1.248E-08 6.064E-11 3.882E-10 6.219E-08 3.525E-09 3.525E-09 6,502E-11 6.502E-11 3.285E-07 2,507E-09 4 086E-09 10.0 1.203E-08 5.844E-11 3 741E-10 5.982E-08 3,400E-09 3,400E-09 6.271E-11 6.271E-11 3.111E-07 2,374E-09 3,870E-09 11.3 1.038E-08 5.044E-11 3.230E-10 5.120E-08 2.945E-09 2.945E-09 5.429E-11 5.429E-11 2.479E-07 1,893E-09 3.084E-09 12.0 94931-09 4.610E-11 2.953E-10 4.653E-08 2 698E-09 2.698E-09 4.973E-11 4.973E-11 2.136E-07 1.631E-09 2 658E-09 14.0 7.01E-09 3.40E-11 2.18E-10 3.35E-08 2.01E-09 2.01E-09 3.70E-11 3.70E-11 1.18E-07 9.03E-10 1.47E-09 14.1 6.933E-09 3.363E-11 2.156E-10 3314E-08 1,990E-09 1.990E-09 3,663E-11 3.663E-11 1.162E-07 8.889E-10 1.448E-09 14.3 6.833E-09 3.315E-11 2.125E-10 3.268E-08 1.964E-09 1.964E-09 31615E-11 3.615E-11 1.138E-07 8.708E-10 1 419E-09 16.0 5.907E-09 2.867E-11 1 837E 10 2.837E-08 1.723E-09 1723E-09 3.170E-11 3.170E-11 9.19E-08 7.02E-10 1.15E-09 17.0 5.372E-09 2.608E-11 1.670E-10 2.588E-08 1.5841-09 15841-09 2.913E-11 2.913E-11 8.450E-08 6.455E-10 1.057E-09 18.1 4.737E-09 2.301E-11 1.473E-10 2.293F-08 1.419E-09 1,419E-09 2.608E-11 2,608E-11 7.574E-08 5,785E-10 9 460E-10 20.0 3.70E-09 1.80E-11 1.15E-1O 1.81E-08 1.15E-09 1.15E-09 2.11E-11 2.11E-11 22.6 3,174E-09 1.544E-11 9.869E-11 1.561E-08 9 908E-10 9 908E-10 1.819E-11 1.819E-11 27.5 2.200E-09 1.070E-11 6.850E-11 1,099E-08 6.96E-10 6.96E-10 1.28E-1I 1.28E-11 29.0 1.90E-09 9.24E-12 5.92E-11 9.57E-09 6.461E 10 6 461E-10 1.190E-11 1.190E-11 31.5 1.64E-09 7.97E-12 5.11E-11 8.30E-09 5.63E-10 5.63E-10 1.04E-11 1.04E-11 38.9 1 174E-09 5.685E-12 3.641E-11 5.922E-09 4.12E-10 4.278E-10 7.60E-12 7.895E-12 41.0 1.04E-09 5.03E-12 3.22E-11 5.24E-09 3,890E-10 7,176E-12 43.8 3.38E-10 6.23E-12 Page 135 of 260 South Texas Project Risk-informed GSI-191 Evaluation Volume 3: CASA Grande Analysis RI-GSI191-V03 Revision 1 Table 5.3.3 -Interpolated relative frequencies vs. break size for pressurizer and small bore line welds (Categories 5A through 6A)Category 5A 5B 5C 5D SE 5F 5G 5H 51 5J 6A-1 6A-2 No. Welds 28* 14 53 4 29 4* 0 4 2 2 1" 23*DEGB (in) 7.34 3.71 4.86 3.71 7.34 7.34 N/A 7.34 4.86 2.38 1.89 2.38 Bra(ize,)
F(LOCA>X)
F(LOCA>X)
F(LOCA>X)
F(LOCA>X)
F(LOCAMX)
F(LOCA>X)
F(LOCA_>)
F(LOCA>_)
F(LOCA?) F(LOCA>X)
F(LOCA>X)
F(LOCA>_)0.5 4.59E-08 4.59E-08 1.72E-08 1.72E-08 1.72E-08 5.09E-06 1.74E-08 1.72E-08 4.59E-08 1.22E-06 1.22E-06 0.9 2.376E-08 2.376E-08 8&874E-09 8&874E-09 8.874E-09 2.633E-06 9.022E-09 8.874E-09 2.376E-08 6 134E-07 6,134E-07 1.0 1.96E-08 1.96E-08 7.33E-09 7.33E-09 7.33E-09 2.17E-06 7.42E-09 7.33E-09 1.96E-08 5.00E-07 5.00E-07 1.2 1.744E-08 1.744E-08 6.523E-09 6.523E-09 6&523E-09 I 933E-06 61604E-09 6,523E-09 1.744E-08 4.363E-07 4 363E-07 1.5 1.24E-08 1.24E-08 4.64E-09 4.64E-09 4.64E-09 1.38E-06 4.70E-09 4.64E-09 1.24E-08 3.08E-07 3.08E-07 1.9 7.907E-09 7.907E-09 2.963E-09 2.963E-09 2,963E-09 8.777E-07 3.000E-09 2.963E-09 7.907E-09 2 021E-07 2,021E-07 2.0 6,64.E-09 6.64E-09 2.49E-09 2.49E-09 2.49E-09 7.36E-07 2,52E-09 2.49E-09 6.64E-09 1.73E-07 2.4 5.162E-09 5.162E-09 1.935E-09 1,935E-09 1.935E-09 5,722E-07 1.958E-09 1.935E-09 5,033E 09 1 320E-07 3.0 2.75E-09 2.75E-09 1.03E-09 1.03E-09 1.03E-09 3.05E-07 1.04E-09 1.03E-09 3.7 1.920E-09 1.920E-09 7,191E-10 7.191E-10 7.191E-10 2 128E-07 7.274E-10 7.191E-10 4.0 1.581E-09 5,921E-10 5 921E-10 1,752E-07 5 997E-10 5,921E-10 4.9 1.006E-09 31765E-10 31765E-10 1 114E-07 3.818E-10 3.765E-10 5.7 6.26E-10 2.34E-10 6.94E-08 2.37E-10 6.0 5.47E-10 2.05E-10 6.06E-08 2.07E-10 6.8 4.16E-10 1.56E-10 4.61E-08 1.58E-10 7.3 3.645E-10 1.366E-10 4,040E-08 1.383E 10 8.5 9.6 10.0 11.3 12.0 14.0 14.1 14.3 16.0 17.0 18.1 20.0 22.6 27.5 29.0 31.5 38.9 41.0 43.8 Page 136 of 260 South Texas Project Risk-Informed GSI-191 Evaluation Volume 3: CASA Grande Analysis RI-GSI191-V03 Revision 1 Table 5.3.4 -Interpolated relative frequencies vs. break size for small bore and safety injection and recirculation line welds (Categories 6B through 7J)Category 6B-1 6B-2 7A 7B 7C 7D 7E 7F 7G 7H 71 7J No. Welds 176 17 21 9 3 3 57 30 42 23 5 8*DEGS (in) 0.87 1.15 14.32 9.64 9.64 14.32 14.32 12.02 9.64 7.34 4.86 3.71 Break Size, X F(LOCAMX)
F(LOCAMX)
F(LOCA2X)
F(LOCAX) F(LOCA.X)
F(LOCAX) F(LOCAX) F(LOCAX) F(LOCAMX)
F(LOCAX) F(LOCAX) F(LOCA?:X)(in) _____ _____0.5 1.22E-06 1.22E-06 2.78E-06 2.78E-06 3.10E-06 3.54E-07 1.14E-08 1.14E-08 1.14E-08 1.14E-08 1.14E-08 1.14E-08 0.9 6.134E-07 6.134E-07 1.435E-06 1.435E-06 1.601E-06 1.827E-07 5,885E-09 5.885E-09 5.885E-09 5.885E-09 5.885E-09 5 885E-09 1.0 5.00E-07 1.18E-06 1.18E-06 1.32E-06 1.51E-07 4.85E-09 4.85E-09 4.85E-09 4.85E-09 4.85E-09 4.85E-09 1.2 4.363E-07 1.050E-06 1.050E-06 1.174E-06 1.343E-07 4.316E-09 4.316E-09 4 316E-09 4.316E-09 4.316E 09 4.316E-09 1.5 7.48E-07 7.48E-07 8.34E-07 9.54E-08 3.07E-09 3.07E-09 3.07E-09 3.07E-09 3.07E-09 3.07E-09 1.9 4.773E-07 4.773E-07 5.329E-07 6.092E-08 1.962E-09 1962E-09 1.962E-09 1.962E-09 1.962E-09 1 962E-09 2.0 4.01E-07 4.01E-07 4.48E-07 5.12E-08 1.65E-09 1.65E-09 1.65E-09 1,65E-09 1.65E-09 1.65E-09 2.4 2.939E-07 2.939E-07 3.280E-07 3.751E-08 1.208E-09 1.208E-09 1.208E-09 1.208E-09 1.208E-09 1 208E 09 3.0 1.551E-07 1.551E-07 1.727E-07 1.977E-08 6.362E-10 6.362E-10 6.362E-10 6.362E-10 6.362E-10 6 362E-10 3.7 1.053E-07 1.053E-07 1.174F-07 1.340E-08 4.323E-10 4.323E-10 4.323E-10 4 323E-10 4.323E-10 4.323E-10 4.0 8.50E-08 8.50E-08 9.48E-08 1.08E-08 3.49E-10 3.49E-10 3.49E-10 3.49E-10 3.49E-10 4.9 5.829E-08 5.829E-08 6.500E-08 7 437E-09 2,394E-10 2.394E-10 2.394E-10 2 394E-10 2 394E-10 5.7 3.79E-08 3.79E-08 4.23E-08 4.84E-09 1.56E-10 1.56E-10 1.56E-10 1.56E-10 6.0 3.31E-08 3.31E-08 3.70E-08 4.23E-09 1.36E-10 1.36E-10 1.36E-10 1.36E-10 6.8 2.52E-08 2.52E-08 2.81E-08 3.22E-09 1.04E-10 1.04E-10 1.04E-10 1.04E-10 7.3 2.153E-08 2.153E-08 2.405E-08 2.744E-09 8,844E-11 8,844E-11 8.844E-11 8,844E-11 8.5 1.60E-08 1.60E-08 1.79E-08 2.04E-09 6.58E-11 6.58E-11 6.58E-11 9.6 1.265E-08 1.265E-08 1 409E-08 1.606E-09 5.186E-11 5.186E-11 5.186E-11 10.0 1.16E-08 1.47E-09 4.75E-11 4.75E-11 11.3 9.11E-09 1.16E-09 3.74E-11 3.74E-11 12.0 8.312F-09 1.059E-09 3,414E-11 3.414E-11 14.0 6.087E-09 7.760E-10 2.504E-11 14.1 5.93E-09 7.56E-10 2.44E-11 14.3 5.810E-09 7.407E-10 2.390E-11 16.0 17.0 18.1 20.0 22.6 27.5 29.0 31.5 38.9 41.0 43.8 Page 137 of 260 South Texas Project Risk-Informed GSI-191 Evaluation Volume 3: CASA Grande Analysis RI-GSI191-V03 Revision 1 Table 5.3.5 -Interpolated relative frequencies vs. break size for safety injection and recirculation, accumulator injection, and CVCS line welds (Categories 7K through 8F and total frequencies)
Category 7K 7L 7M 7N 70 8A 8B SC-1 8C-2 8D 8E 8F No. Welds 11" 0 0 35 15 10 19 8 39 6 4 1 DEGB (in) 2.38 N/A N/A 14.32 14.32 2.38 4.86 1.89 2.38 4.86 4.86 4.86 Break Size, X F(LOCA>X)
F(LOCA>X)
F(LOCA>X)
F(LOCA>X)
F(LOCAX) F(LOCA>X)
F(LOCA>X)
F(LOCA>X)
F(LOCAX) F(LOCA>X)
F(LOCA>X)
F(LOCAX)(in)0.5 1.14E-08 5.18E-08 6.26E-09 4.28E-08 4.28E-08 1.87E-08 1.87E-08 1.87E-08 7.98E-08 1.87E-08 0.9 5,885E-09 2.678E-08 3.227E-09 2.210E-08 2,210E-08 9.650E-09 9.650E-09 9,650E-09 4.123E-08 9.650E-09 1.0 4.85E-09 2.21E-08 2.66E-09 1.82E-08 1.82E-08 7.97E-09 7.97E-09 7.97E-09 3.40E-08 7.97E-09 1.2 4.316E-09 1.967E-08 2.369E-09 1 619F-08 1,619E-08 7.091E-09 7.091E-09 7.091E-09 3 025E-08 7,091E-09 1.5 3.07E-09 1.40E-08 1.69E-09 1.15E-08 1.15E-08 5.04E-09 5.04E-09 5.04E-09 2.15E-08 5.04E-09 1.9 L962E-09 8922E-09 1.077E-09 7.233E-09 7.233E-09 3.168E-09 3.168E-09 3.168E-09 1.347E-08 3.168E-09 2.0 1.65E-09 7.49E-09 9.04E-10 6.03E-09 6.03E-09 2.64E-09 2.64E-09 1.12E-08 2.64E-09 2.4 1.208E-09 5.489E-09 6,623E-10 4 658E-09 4.658E-09 2.040E-09 2.040E-09 8 658E-09 2.040E-09 3.0 2.909E109 3.507E-10 2.42E-09 1.06E-09 4.51E-09 1.06E-09 3.7 2.029E-09 2.451E-10 1.596E-09 6 972E-10 2 969E-09 6972E-10 4.0 1.67E-09 2.02E-10 1.26E-09 5.49E-10 2.34E-09 5.49E-10 4.9 1172E-09 1.416E-LO 9.062E-10 3.951E-10 1.687E-09 3,951E-10 5.7 7.09E-10 8.55E-11 6.0 6.19E-10 7.47E-11 6.8 4.803E-10 5.801E-11 7.3 4.0411-10 4.881E-11 8.5 13228E-10 3.899E-11 9.6 2.415E-10 2 917E-11 10.0 2.16E-10 2.61E-11 11.3 1.828F-10 2.208E-11 12.0 1,648E-10 1,990E-11 14.0 1.146E-10 1383E-11 14.1 1.111-10 1.34E-11 14.3 1.087E-10 1.313E-11 16.0 17.0 18.1 20.0 22.6 27.5 29.0 31.5 38.9 41.0 43.8 Page 138 of 260 South Texas Project Risk-Informed GSI-191 Evaluation Volume 3: CASA Grande Analysis RI-GSI191-V03 Revision 1 Table 5.3.6 shows the total relative frequency for each break size calculated by multiplying the relative frequency for a given weld category by the number of welds in that category and summing the results for all weld categories.
Freqrelative[LOCA
_ X at all welds] = Freqrelative[LOCA
> X at Weldi]
- ni where: Equation 30 Freqrelative
= Relative frequency X = Break size Weld 1 = Weld category (1A, 1B, etc.)ni = Number of welds within the weld category The relative frequencies for each weld category can be divided by the total relative frequency at each break size to determine the relative contribution of each category to the total frequency.
An example of this is provided in Table 5.3.7 for a 1.5-inch small break, a 4-inch medium break, and a 10-inch large break.Table 5.3.6 -Total relative frequency vs. break size Total Relative Break Size, X eqnc (in) Frequency (year 1)0.5 4.11E-04 0.9 2.13E-04 1.0 8.73E-05 1.2 7.66E-05 1.5 4.71E-05 1.9 3.11E-05 2.0 2.65E-05 2.4 2.03E-05 3.0 9.95E-06 3.7 6.99E-06 4.0 5.78E-06 4.9 4.18E-06 5.7 2.88E-06 6.0 2.53E-06 6.8 2.OOE-06 7.3 1.81E-06 8.5 1.34E-06 9.6 1.13E-06 10.0 9.13E-07 Page 139 of 260 South Texas Project Risk-Informed GSI-191 Evaluation Volume 3: CASA Grande Analysis RI-GSI191-V03 Revision 1 Total Relative Break Size, X Frqec (in) Frequency (year" 1)11.3 7.45E-07 12.0 6.65E-07 14.0 4.43E-07 14.1 4.36E-07 14.3 4.28E-07 16.0 2.52E-07 17.0 2.30E-07 18.1 2.05E-07 20.0 9.75E-08 22.6 8.40E-08 27.5 5.90E-08 29.0 5.16E-08 31.5 4.48E-08 38.9 3.21E-08 41.0 2.69E-08 43.8 1.50E-09 Table 5.3.7 -Relative contribution of each weld category to total LOCA frequencies We Maximum No. Relative Relative Relative Break (DEGB) Contribution for Contribution Contribution Size (in) 1.5-in Break for 4-in Break for 10-in Break 1A 41.01 4 0.79% 2.21% 5.27%1B 41.01 11 0.01% 0.03% 0.07%IC 41.01 1 0.01% 0.02% 0.04%2 41.01 4 3.90% 11.07% 26.20%3A 38.89 4 0.29% 0.66% 1.49%3B 43.84 4 0.29% 0.66% 1.49%3C 38.89 12 0.02% 0.04% 0.08%3D 43.84 24 0.03% 0.07% 0.16%4A 18.12 1 7.01% 17.82% 34.06%4B 18.12 7 0.37% 0.95% 1.82%4C 18.12 2 0.17% 0.44% 0.85%4D 3.01 6 0.32% 0.00% 0.00%5A 7.34 28 0.74% 0.77% 0.00%5B 3.71 14 0.37% 0.00% 0.00%5C 4.86 53 0.52% 0.54% 0.00%5D 3.71 4 0.04% 0.00% 0.00%5E 7.34 29 0.29% 0.30% 0.00%5F 7.34 4 11.72% 12.12% 0.00%Page 140 of 260 South Texas Project Risk-Informed GSI-191 Evaluation Volume 3: CASA Grande Analysis RI-GSI191-V03 Revision 1 Weld Maximum No. Relative Relative Relative Break (DEGB) Contribution for Contribution Contribution Size (in) 1.5-in Break for 4-in Break for 10-in Break 5G N/A 0 0.00% 0.00% 0.00%5H 7.34 4 0.04% 0.04% 0.00%51 4.86 2 0.02% 0.02% 0.00%5. 2.38 2 0.05% 0.00% 0.00%6A-1 1.89 1 0.65% 0.00% 0.00%6A-2 2.38 23 15.05% 0.00% 0.00%6B-1 0.87 176 0.00% 0.00% 0.00%6B-2 1.15 17 0.00% 0.00% 0.00%7A 14.32 21 33.36% 30.88% 26.67%7B 9.64 9 14.30% 13.24% 0.00%7C 9.64 3 5.31% 4.92% 0.00%7D 14.32 3 0.61% 0.56% 0.48%7E 14.32 57 0.37% 0.34% 0.30%7F 12.02 30 0.20% 0.18% 0.16%7G 9.64 42 0.27% 0.25% 0.00%7H 7.34 23 0.15% 0.14% 0.00%71 4.86 5 0.03% 0.03% 0.00%71 3.71 8 0.05% 0.00% 0.00%7K 2.38 11 0.07% 0.00% 0.00%7L N/A 0 0.00% 0.00% 0.00%7M N/A 0 0.00% 0.00% 0.00%7N 14.32 35 1.04% 1.01% 0.83%70 14.32 15 0.05% 0.05% 0.04%8A 2.38 10 0.24% 0.00% 0.00%8B 4.86 19 0.46% 0.41% 0.00%8C-1 1.89 8 0.09% 0.00% 0.00%8C-2 2.38 39 0.42% 0.00% 0.00%8D 4.86 6 0.06% 0.06% 0.00%8E 4.86 4 0.18% 0.16% 0.00%8F 4.86 1 0.01% 0.01% 0.00%Total N/A 786 100% 100% 100%5.3.2 Weld Categories and Coordinates The weld categories and locations for each weld were determined based on a LOCA frequency component database (9) and the containment building CAD model (4). Both the database and CAD model are based on STP's in-service inspection (ISI) drawings.
Table 5.3.9 shows the relevant weld data from these two sources. Note that there were a few discrepancies between the LOCA frequency report Page 141 of 260 South Texas Project Risk-Informed GSI-191 Evaluation Volume 3: CASA Grande Analysis RI-GSI191-V03 Revision 1 (7), the component database (9), and the CAD model (4). The discrepancies are listed below and were corrected in Table 5.3.9. Note that the corrections are marked with an asterisk." Weld 31-RC-1102-NSS-5 is listed in the database as Category 71 on a 3-inch pipe. However, according to the CAD model, this is a 2-inch pipe and therefore the weld falls within Category 7K.* The component database was updated with a modification to the weld category identifiers after the LOCA frequency report was issued. Category 5G corresponds to B-J welds on 6-inch pressurizer piping susceptible to failures from D&C and PWSCC damage mechanisms.
Four welds at STP that fit this category have weld overlays that eliminate the PWSCC damage mechanism.
This was evaluated as a Category 5G sensitivity in the component database, but was included as Category 5H in the LOCA frequency report. Similarly, Categories 5H and 51 in the component database correspond to Categories 51 and 51 in the LOCA frequency report. To clear this up, the welds falling in these categories were adjusted in Table 5.3.9 to match the categories identified in the LOCA frequency report.* Twenty-one 2-inch welds that are included in the CAD model were not explicitly identified in the component database.
These welds were assigned to Category 6A." As discussed in Section 5.3.1, the pipe size provided in the LOCA frequency report is the nominal pipe diameter.
The actual pipe diameter is typically smaller than the nominal diameter, which also affects the equivalent DEGB size. The pipe diameter differences between the LOCA frequency report and the CAD model are shown in Table 5.3.8.* There are also a few differences between the weld count provided in the LOCA frequency report and the CAD model as shown in Table 5.3.8. The most notable difference is the weld count for Category 6B. The LOCA frequency report lists 193 welds in this category, but the CAD model and the component database only contain a total of 35 of these welds. Upon review, the missing welds appear to be locations where 0.75-inch pipes (drain lines, etc.) are connected to larger piping. As shown in Figure 5.3.1, the 35 welds that were modeled are scattered throughout containment.
Given the scattered distribution, and the relatively low significance with respect to GSI-191 phenomena for this size of breaks, it is reasonable to distribute the overall break frequency for the 193 welds to the 35 welds that were modeled (see Assumption 3.e). For other weld categories, the weld count in the CAD model was assumed to be more accurate than the weld count in the LOCA frequency report (see Assumption 3.f).Table 5.3.8 -Comparison of LOCA frequency report and CAD model pipe sizes and weld counts Ct Report Pipe CAD Pipe Report CAD DEGB Report Weld CAD Weld Size (in) Size (in) DEGB (in) (in) Count Count 6B-1 0.614 0.87 32 11.4119 6B-2 0.815 1.15 3 7L 1.5 N/A 2.12 N/A 0 0 Page 142 of 260 South Texas Project Risk-Informed GSI-191 Evaluation Volume 3: CASA Grande Analysis RI-GS1191-V03 Revision 1 C Report Pipe CAD Pipe Report CAD DEGB Report Weld CAD Weld ategory Size (in) Size (in) DEGB (in) (in) Count Count 5J 2 1.689 2.83 2.38 2 2 6A-1 2 1.338 283 1.89 1 6A-2 1.689 2.38 23 7K 2 1.689 2.83 2.38 10 11 8A 2 1.689 2.83 2.38 10 10 8C-1 2 1.338 2.83 1.89 8 8C-2 1.689 2.38 39 4D 2.5 2.125 3.54 3.01 6 6 5B 3 2.626 4.24 3.71 14 14 5D 3 2.626 4.24 3.71 4 4 7J 3 2.626 4.24 3.71 9 8 5C 4 3.438 5.66 4.86 53 53 51 4 3.438 5.66 4.86 2 2 71 4 3.438 5.66 4.86 5 5 8B 4 3.438 5.66 4.86 19 19 8D 4 3.438 5.66 4.86 6 6 8E 4 3.438 5.66 4.86 4 4 8F 4 3.438 5.66 4.86 1 1 5A 6 5.189 8.49 7.34 29 28 5E 6 5.189 8.49 7.34 29 29 5F 6 5.189 8.49 7.34 0 4 5G 6 N/A 8.49 N/A 0 0 5H 6 5.189 8.49 7.34 4 4 7H 6 5.189 8.49 7.34 23 23 7B 8 6.813 11.31 9.64 9 9 7C 8 6.813 11.31 9.64 3 3 7G 8 6.813 11.31 9.64 42 42 7F 10 8.500 14.14 12.02 30 30 7A 12 10.126 16.97 14.32 21 21 7D 12 10.126 16.97 14.32 3 3 7E 12 10.126 16.97 14.32 57 57 7M 12 N/A 16.97 N/A 0 0 7N 12 10.126 16.97 14.32 35 35 70 12 10.126 16.97 14.32 15 15 4A 16 12.814 22.63 18.12 1 1 4B 16 12.814 22.63 18.12 7 7 4C 16 12.814 22.63 18.12 2 2 3A 27.5 27.500 38.89 38.89 4 4 3C 27.5 27.500 38.89 38.89 12 12 1A 29 29.000 41.01 41.01 4 4 1B 29 29.000 41.01 41.01 11 11 IC 29 29.000 41.01 41.01 1 1 Page 143 of 260 South Texas Project Risk-Informed GSI-191 Evaluation Volume 3: CASA Grande Analysis RI-GSI191-V03 Revision 1 Report Pipe CAD Pipe Report CAD DEGB Report Weld CAD Weld Size (in) Size (in) DEGB (in) (in) Count Count 2 29 29.000 41.01 41.01 4 4 3B 31 31.000 43.84 43.84 4 4 3D 31 31.000 43.84 43.84 24 24 Total 1 775 628 Figure 5.3.1 -Locations of Category 6B welds that were modeled Page 144 of 260 South Texas Project Risk-Informed GSI-191 Evaluation Volume 3: CASA Grande Analysis RI-GSI191-V03 Revision 1 Table 5.3.9 -Weld data from component database and CAD model No. Line Number Location Name System Category Pipe ID X Y Z Side Compartment 1 2-CV-1122-BB1 0.75-CV-1122-BBi-1 CV Small Bore 6B-1 0.614 -391.858 -245.642 497.125 Cold SG Compartment 2 2-CV-1122-BB1 0.75-CV-1122-BB1-2 CV Small Bore 6B-1 0.614 -391.858 -260.642 513 Cold SG Compartment 3 2-CV-1124-BB1 0.75-CV-1124-BBI-1 CV Small Bore 6B-1 0.614 -334.812 342.313 513 Cold SG Compartment 4 2-CV-1124-BB1 0.75-CV-1124-BB1-2 CV Small Bore 68-1 0.614 -334.812 329.313 525 Cold SG Compartment 5 2-CV-1126-BB1 0.75-CV-1126-BB1-1 CV Small Bore 6B-1 0.614 399 269.313 477 Cold SG Compartment 6 2-CV-1126-BB1 0.75-CV-1126-BB1-2 CV Small Bore 6B-1 0.614 399 260.313 513 Cold SG Compartment 7 2-CV-1128-BB1 0.75-CV-1128-BBi-1 CV Small Bore 6B-1 0.614 350.702 -324.25 563.438 Cold SG Compartment 8 2-CV-1128-BB1 0.75-CV-1128-BB1-2 CV Small Bore 6B-1 0.614 341.702 -324.25 563.438 Cold SG Compartment 9 4-RC-1003-BBI 0.75-RC-1001-BB1-1 RC Small Bore 6B-1 0.614 108.001 -648.001 998 Cold PZR Compartment 10 4-RC-1000-BB1 0.75-RC-1002-BB2-1 RC Small Bore 6B-1 0.614 97.812 -594.189 998 Cold PZR Compartment 11 12-RC-1112-BB1 0.75-RC-1112-BB1-1 RC Small Bore 68-1 0.614 -30.55 -261.662 456.035 Hot SG Compartment 12 8-RC-1114-8B1 0.75-RC-1114-BB1-1 RC Small Bore 6B-1 0.614 -141.33 -226.374 483 Hot SG Compartment 13 12-RC-1125-BB1 0.75-RC-1125-BB1-1 Sl-ACC-CL1 Small Bore 6B-1 0.614 -270.999 -310.539 548.204 Cold SG Compartment 14 12-RC-1125-BB1 0.75-RC-1125-BB1-2 Sl-ACC-CL1 Small Bore 6B-1 0.614 -265.077 -384.343 273.017 Cold Below SG Compartment 15 4-RC-1126-BB1 0.75-RC-1126-BB1-1 RC Small Bore 6B-1 0.614 -236 -91.56 507 Cold SG Compartment 16 12-RC-1212-BB1 0.75-RC-1212-BB1-1 RC Small Bore 6B-1 0.614 -30.551 261.636 456.007 Hot SG Compartment 17 8-RC-1214-BB1 0.75-RC-1214-BB1-1 RC Small Bore 6B-1 0.614 -143.269 225.591 483 Hot SG Compartment 18 12-RC-1221-BB1 0.75-RC-1221-BB1-1 Sl-ACC-CL2 Small Bore 6B-1 0.614 -270.999 310.309 548.169 Cold SG Compartment 19 12-RC-1221-BB1 0.75-RC-1221-BB1-2 SI-ACC-CL2 Small Bore 68-1 0.614 -265.077 384.113 273.006 Cold Below SG Compartment 20 12-RC-1312-BB1 0.75-RC-1312-BB1-1 RC Small Bore 6B-1 0.614 54.55 261.662 455.999 Hot SG Compartment 21 8-RC-1324-BB1 0.75-RC-1324-BB1-1 RC Small Bore 68-1 0.614 165.148 223.469 492 Hot SG Compartment 22 4-RC-1422-BB1 0.75-RC-1423-BB1-1 RC Small Bore 6B-1 0.614 108.001 -612.751 984 Cold PZR Compartment 23 8-SI-1108-BB1 0.75-SI-1130-BB2-1 RC Small Bore 6B-1 0.614 -310.37 -395.39 483 Hot SG Compartment 24 12-51-1125-BB1 0.75-SI-1132-BB1-1 RC Small Bore 6B-1 0.614 -390.942 -354.644 273.017 Cold Below SG Compartment 25 12-S1-1218-BB1 0.75-51-1218-BB1-1 SI Small Bore 6B-1 0.614 -364.072 381.285 273.006 Cold Below SG Compartment 26 8-SI-1208-BB1 0.75-51-1223-B82-1 RC Small Bore 6B-1 0.614 -313.12 395.46 483 Hot SG Compartment 27 12-SI-1315-BB1 0.75-SI-1315-BB1-1 SI-ACC Small Bore 68-1 0.614 312.427 331.154 548.194 Cold SG Compartment 28 12-SI-1315-BB1 0.75-S1-1323-BB1-1 SI-ACC Small Bore 6B-1 0.614 345.971 364.697 191.014 Cold Below SG Compartment 29 6-SI-1327-BB1 0.75-51-1327-BB1-1 SI Small Bore 68-1 0.614 361.366 383.719 491.924 Hot SG Compartment 30 8-SI-1327-BB1 0.75-SI-1327-B81-2 SI Small Bore 6B-1 0.614 335.604 393.925 540 Hot SG Compartment 31 8-SI-1327-BB1 0.75-SI-1327-BB1-3 SI Small Bore 6B-1 0.614 200.944 259.265 492 Hot SG Compartment 32 8-SI-1327-BB1 0.75-Sl-1328-B82-1 SI Small Bore 6B-1 0.614 360.352 397.461 491.924 Hot SG Compartment 33 6-RC-1003-BB1 1-RC-1003-BB1-1 RC Small Bore 6B-2 0.815 53.272 -636.728 1263 Cold PZR Compartment 34 4-RC-1123-BB1 1-RC-1123-BB1-1 RC Small Bore 6B-2 0.815 -18.187 -516.189 807 Cold SG Compartment 35 4-RC-1422-BB1 1-RC-1422-BBi-1 RC Small Bore 6B-2 0.815 108.001 -607.626 984 Cold PZR Compartment 36 16-RC-1412-NSS 1.5-RC-1412-NSS-1 RC 6A-1 1.338 165.003 -507 526.221 Hot SG Compartment 37 2(1.5)-CV-1122-BB1 2(1.5)-CV-1122-BB1-1 CV -RCP1A 8C-1 1.338 -391.86 -260.64 551.44 Cold SG Compartment 38 2(1.5)-CV-1122-BB1 2(1.5)-CV-1122-BB1-2 CV -RCP1A 8C-1 1.338 -381.8 -260.64 563.44 Cold SG Compartment 39 2(1.5)-CV-1124-BB1 2(1.5)-CV-1124-BB1-1 CV -RCP1B 8C-1 1.338 -334.81 323.31 563.44 Cold SG Compartment Page 145 of 260 South Texas Project Risk-Informed GSI-191 Evaluation Volume 3: CASA Grande Analysis RI-GSI191-V03 Revision 1 No. Line Number Location Name System Category Pipe ID X Y Z Side Compartment 40 2(1.5)-CV-1124-BB1 2(1.5)-CV-1124-BB1-2 CV -RCP1B 8C-1 1.338 -334.81 311.44 563.44 Cold SG Compartment 41 2(i.5)-CV-1126-BB1 2(1.5)-CV-1126-BB1-1 CV -RCP1C 8C-1 1.338 393 260.31 563.44 Cold SG Compartment 42 2(i.5)-CV-1126-BB1 2(1.5)-CV-1126-BB1-2 CV -RCPIC SC-1 1.338 385.94 260.31 563.44 Cold SG Compartment 43 2(i.5)-CV-1128-BBI 2(1.5)-CV-1128-BB1-1 CV -RCP1D 8C-1 1.338 332.7 -318.12 563.44 Cold SG Compartment 44 2(i.5)-CV-1128-BBI 2(1.5)-CV-1128-BB1-2 CV -RCP1D 8C-1 1.338 332.7 -309.56 563.44 Cold SG Compartment 45 2-CV-1121-BB1 2-CV-1121-B81-1 CV -PZR Auxiliary Spray Line 8A 1.689 11 -588.25 984 Cold PZR Compartment 46 2-CV-1121-BB1 2-CV-1121-BB1-2 CV -PZR Auxiliary Spray Line 8A 1.689 44.93 -588.25 1062 Cold PZR Compartment 47 2-CV-1121-BB1 2-CV-1121-BBI-3 CV -PZR Auxiliary Spray Line 8A 1.689 108 -621.5 1062 Cold PZR Compartment 48 2-CV-1122-B81 2-CV-1122-BBI-1 CV -RCPIA 8C-2 1.689 -391.86 -212.64 497.12 Cold SG Compartment 49 2-CV-1122-BBI 2-CV-1122-BB1-2 CV -RCPIA 8C-2 1.689 -391.86 -221.64 497.12 Cold SG Compartment 50 2-CV-1122-BB1 2-CV-1122-BB1-3 CV -RCP1A 8C-2 1.689 -391.86 -229.64 497.12 Cold SG Compartment 51 2-CV-1122-BB1 2-CV-1122-BB1-4 CV -RCPIA 8C-2 1.689 -391.86 -242.64 497.12 Cold SG Compartment 52 2-CV-1122-BB1 2-CV-1122-BB1-5 CV -RCP1A 8C-2 1.689 -391.86 -248.64 497.12 Cold SG Compartment 53 2-CV-1122-BB1 2-CV-1122-BB1-6 CV -RCPIA 8C-2 1.689 -391.86 -260.64 548.44 Cold SG Compartment 54 2-CV-1124-BB1 2-CV-1124-BB1-1 CV -RCP1B 8C-2 1.689 -325.97 377.65 513 Cold SG Compartment 55 2-CV-1124-BB1 2-CV-1124-B81-2 CV -RCPSB 8C-2 1.689 -332.69 370.93 513 Cold SG Compartment 56 2-CV-1124-B81 2-CV-1124-BB1-3 CV -RCP1B 8C-2 1.689 -334.81 365.81 513 Cold SG Compartment 57 2-CV-1124-BB1 2-CV-1124-BBI-4 CV -RCP1B 8C-2 1.689 -334.81 359.31 513 Cold SG Compartment 58 2-CV-1124-BB1 2-CV-1124-BBI-5 CV -RCPIB 8C-2 1.689 -334.81 351.31 513 Cold SG Compartment 59 2-CV-1124-BB1 2-CV-1124-BBI-6 CV -RCPIB 8C-2 1.689 -334.81 345.31 513 Cold SG Compartment 60 2-CV-1124-BB1 2-CV-1124-B13-7 CV -RCPIB 8C-2 1.689 -334.81 339.31 513 Cold SG Compartment 61 2-CV-1124-BB1 2-CV-1124-BB1-8 CV -RCPIB 8C-2 1.689 -334.81 332.31 513 Cold SG Compartment 62 2-CV-1124-BB1 2-CV-1124-B13-9 CV -RCP1B 8C-2 1.689 -334.81 329.31 516 Cold SG Compartment 63 2-CV-1124-BB1 2-CV-1124-B81-10 CV -RCPIB 8C-2 1.689 -334.81 329.31 522 Cold SG Compartment 64 2-CV-1124-BB1 2-CV-1124-BB1-11 CV -RCP1B 8C-2 1.689 -334.81 329.31 528 Cold SG Compartment 65 2-CV-1124-BB1 2-CV-1124-BB1-12 CV -RCP1B 8C-2 1.689 -334.81 329.31 560.44 Cold SG Compartment 66 2-CV-1124-BB1 2-CV-1124-BB1-13 CV -RCPIB 8C-2 1.689 -334.81 326.31 563.44 Cold SG Compartment 67 2-CV-1126-BB1 2-CV-1126-BB1-1 CV -RCP1C BC-2 1.689 399 293.81 477 Cold SG Compartment 68 2-CV-1126-BB1 2-CV-1126-B13-2 CV -RCP1C 8C-2 1.689 399 286.81 477 Cold SG Compartment 69 2-CV-1126-BB1 2-CV-1126-BBI-3 CV -RCPiC 8C-2 1.689 399 278.81 477 Cold SG Compartment 70 2-CV-1126-BB1 2-CV-1126-B81-4 CV -RCPlC 8C-2 1.689 399 272.81 477 Cold SG Compartment 71 2-CV-1126-BB1 2-CV-1126-BB1-5 CV -RCP1C 8C-2 1.689 399 266.31 477 Cold SG Compartment 72 2-CV-1126-8B1 2-CV-1126-BB1-6 CV -RCP1C 8C-2 1.689 399 263.31 477 Cold SG Compartment 73 2-CV-1126-BB1 2-CV-1126-BB1-7 CV -RCP1C 8C-2 1.689 399 260.31 480 Cold SG Compartment 74 2-CV-1126-BB1 2-CV-1126-B81-8 CV -RCP1C 8C-2 1.689 399 260.31 510 Cold SG Compartment 75 2-CV-1126-BBI 2-CV-1126-BBI-9 CV -RCP1C 8C-2 1.689 399 260.31 516 Cold SG Compartment 76 2-CV-1126-B81 2-CV-1126-BB1-10 CV -RCP1C 8C-2 1.689 399 260.31 560.44 Cold SG Compartment 77 2-CV-1126-BB1 2-CV-1126-BB1-11 CV -RCP1C 8C-2 1.689 396 260.31 563.44 Cold SG Compartment 78 2-CV-1128-BB1 2-CV-1128-BBi-i CV -RCP1D 8C-2 1.689 379.7 -324.25 563.44 Cold SG Compartment 79 2-CV-1128-BB1 2-CV-1128-B13-2 CV -RCP1D 8C-2 1.689 367.7 -324.25 563.44 Cold SG Compartment 80 2-CV-1128-BB1 2-CV-112B-B81-3 CV -RCP1D 8C-2 1.689 359.7 -324.25 563.44 Cold SG Compartment Page 146 of 260 South Texas Project Risk-Informed GSI-191 Evaluation Volume 3: CASA Grande Analysis RI-GSI191-V03 Revision 1 No. Line Number Location Name System Category Pipe ID X Y Z Side Compartment 81 2-CV-1128-BB1 2-CV-1128-BB1-3A CV -RCPID 8C-2 1.689 353.7 -324.25 563.44 Cold SG Compartment 82 2-CV-1128-BB1 2-CV-1128-BB1-3B CV -RCP1D 8C-2 1.689 347.7 -324.25 563.44 Cold SG Compartment 83 2-CV-1128-BB1 2-CV-1128-BB1-4 CV -RCP1D 8C-2 1.689 344.7 -324.25 563.44 Cold SG Compartment 84 2-CV-1128-BB1 2-CV-1128-BB1-5 CV -RCP1D 8C-2 1.689 338.7 -324.25 563.44 Cold SG Compartment 85 2-CV-1128-BB1 2-CV-1128-BB1-6 CV -RCPID 8C-2 1.689 335.7 -324.25 563.44 Cold SG Compartment 86 2-CV-1128-BB1 2-CV-1128-BB1-7 CV -RCPID 8C-2 1.689 332.7 -321.12 563.44 Cold SG Compartment 87 2-CV-1141-BB1 2-CV-1141-BB1-1 CV -RC Crossover-4 8A 1.689 243 -209.06 372 Cold SG Compartment 88 2-CV-1141-BB1 2-CV-1141-BB1-2 CV -RC Crossover-4 8A 1.689 255 -186.06 372 Cold SG Compartment 89 2-RC-1003-BB1 2-RC-1003-BB1-1 PZR Auxiliary Spray Line 5J* 1.689 108 -621.5 1062 Cold PZR Compartment 90 2-RC-1003-BB1 2-RC-1003-BB1-2 PZR Auxiliary Spray Line 5J* 1.689 108 -630 1062 Cold PZR Compartment 91 2-RC-1120-BB1 2-RC-1120-BB1-1 RC 7K 1.689 -252 -323 429.14 Cold SG Compartment 92 2-RC-1120-BB1 2-RC-1120-BB1-2 RC 6A-2 1.689 -252 -323.001 433 Cold SG Compartment 93 2-RC-1121-BB1 2-RC-1121-BB1-1 RC 6A-2* 1.689 -271.125 -306.08 380.001 Cold SG Compartment 94 2-RC-1121-BB1 2-RC-1121-BB1-2 RC 6A-2* 1.689 -228 -293.08 372.001 Cold SG Compartment 95 2-RC-1121-BB1 2-RC-1121-BB1-3 RC 6A-2* 1.689 -228 -287.187 372.001 Cold SG Compartment 96 2-RC-1121-BB1 2-RC-1121-BB1-3A RC Drain 6A-2 1.689 -228 -283.19 372 Cold SG Compartment 97 2-RC-1121-BB1 2-RC-1121-BB1-38 RC Drain 6A-2 1.689 -228 -275.19 372 Cold SG Compartment 98 2-RC-1121-B81 2-RC-1121-BB1-4 RC 6A-2* 1.689 -228 -269.187 372.001 Cold SG Compartment 99 2-RC-1219-BB1 2-RC-1219-BB1-1 RC 7K 1.689 -249.25 325.43 429.08 Cold SG Compartment 100 2-RC-1219-BB1 2-RC-1219-BB1-2 RC 6A-2* 1.689 -249.25 325.434 433 Cold SG Compartment 101 2-RC-1220-BB1 2-RC-1220-BB1-1 RC 6A-2* 1.689 -271.146 306.062 379.001 Cold SG Compartment 102 2-RC-1220-BB1 2-RC-1220-BB1-2 RC 6A-2* 1.689 -228 293 369.751 Cold SG Compartment 103 2-RC-1220-BB1 2-RC-1220-BB1-3 RC 6A-2* 1.689 -228 284.5 369.751 Cold SG Compartment 104 2-RC-1220-BB1 2-RC-1220-BB1-4 RC 6A-2* 1.689 -228 275.5 369.751 Cold SG Compartment 105 2-RC-1319-BB1 2-RC-1319-BB1-1 RC 7K 1.689 272.81 325.82 427.58 Cold SG Compartment 106 2-RC-1319-BB1 2-RC-1319-BB1-2 RC 6A-2* 1.689 272.812 325.821 433 Cold SG Compartment 107 2-RC-1321-BB1 2-RC-1321-BB1-1 RC 6A-2* 1.689 244.134 288.072 372.313 Cold SG Compartment 108 2-RC-1321-BB1 2-RC-1321-B81-4 RC 6A-2" 1.689 256.509 276.822 372.313 Cold SG Compartment 109 2-RC-1321-BB1 2-RC-1321-BB1-5 RC 6A-2* 1.689 256.509 268.322 372.313 Cold SG Compartment 110 2-RC-1321-BB1 2-RC-1321-BB1-6 RC 6A-2* 1.689 256.509 259.322 372.313 Cold SG Compartment 111 2-RC-1417-B81 2-RC-1417-BB1-1 RC 7K 1.689 273.37 -325.32 429.33 Cold SG Compartment 112 2-RC-1417-BB1 2-RC-1417-B81-2 RC 6A-2* 1.689 273.375 -325.323 433 Cold SG Compartment 113 2-RC-1418-BB1 2-RC-1418-681-1 RC 6A-2* 1.689 295.146 -306.062 379.293 Cold SG Compartment 114 2-RC-1418-BB1 2-RC-1418-BB1-2 CV -RC Crossover-4 8A 1.689 262.02 -306.06 372 Cold SG Compartment 115 2-RC-1418-BB1 2-RC-1418-8B1-3 CV -RC Crossover-4 8A 1.689 258.02 -302.06 372 Cold SG Compartment 116 2-RC-1418-BB1 2-RC-1418-BB1-4 RC 6A-2* 1.689 258.021 -294.812 372 Cold SG Compartment 117 2-RC-1418-BB1 2-RC-1418-BB1-5 RC 6A-2* 1.689 258.021 -284.812 372 Cold SG Compartment 118 2-RC-1418-BB1 2-RC-1418-BB1-6 RC 6A-2* 1.689 258.021 -271.312 372 Cold SG Compartment 119 2-RC-1419-BB1 2-RC-1419-BB1-1 CV -RC Crossover-4 8A 1.689 254.02 -306.06 372 Cold SG Compartment 120 2-RC-1419-BB1 2-RC-1419-BB1-2 CV -RC Crossover-4 8A 1.689 243 -294.81 372 Cold SG Compartment 121 2-RC-1419-BB1 2-RC-1419-BB1-3 CV -RC Crossover-4 8A 1.689 243 -284.81 372 Cold SG Compartment Page 147 of 260 South Texas Project Risk-Informed GSI-191 Evaluation Volume 3: CASA Grande Analysis RI-GSI191-V03 Revision 1 No. Line Number Location Name System Category Pipe ID X Y Z Side Compartment 122 2-RC-1419-BB1 2-RC-1419-BB1-4 RC 6A-2* 1.689 243 -218.312 372 Cold SG Compartment 123 2.5-RC-1003-BB1 2.5-RC-1003-BB1-1 Pressurizer Surge Line 4D 2.125 46.2 -643.8 1266 Cold PZR Compartment 124 2.5-RC-1003-BB1 2.5-RC-1003-BB1-2 Pressurizer Surge Line 4D 2.125 46.2 -643.8 1272.31 Cold PZR Compartment 125 2.5-RC-1003-BB1 2.5-RC-1003-B81-3 Pressurizer Surge Line 4D 2.125 44.08 -645.92 1275.31 Cold PZR Compartment 126 2.5-RC-1003-BB1 2.5-RC-1003-BB1-4 Pressurizer Surge Line 4D 2.125 41.25 -648.75 1275.31 Cold PZR Compartment 127 2.5-RC-1003-BB1 2.5-RC-1003-BB1-5 Pressurizer Surge Line 4D 2.125 32.19 -657.81 1275.31 Cold PZR Compartment 128 2.5-RC-1003-BB1 2.5-RC-1003-BB1-6 Pressurizer Surge Line 4D 2.125 30.07 -659.93 1275.31 Cold PZR Compartment 129 3-RC-1003-BB1 3-RC-1003-BB1-1 PZR Auxiliary Spray Line 53 2.626 108 -636 1062 Cold PZR Compartment 130 3-RC-1003-BB1 3-RC-1003-8B1-2 PZR Auxiliary Spray Line 5B 2.626 108 -645 1062 Cold PZR Compartment 131 3-RC-1015-NSS 3-RC-1015-NSS-1 Pressurizer PORV Line SD 2.626 -44.11 -652.56 1262.06 Cold PZR Compartment 132 3-RC-1015-NSS 3-RC-1015-NSS-2 Pressurizer PORV Line 5D 2.626 -46.2 -655.24 1260.66 Cold PZR Compartment 133 3-RC-1015-NSS 3-RC-1015-NSS-3 Pressurizer PORV Line 5B 2.626 -48.29 -657.91 1259.25 Cold PZR Compartment 134 3-RC-1015-NSS 3-RC-1015-NSS-4 Pressurizer PORV Line 5B 2.626 -54.45 -665.79 1259.25 Cold PZR Compartment 135 3-RC-1015-NSS 3-RC-1015-NSS-5 Pressurizer PORV Line 5B 2.626 -59.99 -672.89 1259.25 Cold PZR Compartment 136 3-RC-1015-NSS 3-RC-1015-NSS-6 Pressurizer PORV Line 5B 2.626 -69.2 -684.67 1259.25 Cold PZR Compartment 137 3-RC-1015-NSS 3-RC-1015-NSS-7 Pressurizer PORV Line 5B 2.626 -68.43 -691.14 1259.25 Cold PZR Compartment 138 3-RC-1015-NSS 3-RC-1015-NSS-8 Pressurizer PORV Line 5B 2.626 -48.48 -706.73 1259.25 Cold PZR Compartment 139 3-RC-1015-NSS 3-RC-1015-NSS-9 Pressurizer PORV Line 5D 2.626 -26.26 -629.71 1262.06 Cold PZR Compartment 140 3-RC-1015-NSS 3-RC-1015-NSS-10 Pressurizer PORV Line 5D 2.626 -24.16 -627.04 1260.66 Cold PZR Compartment 141 3-RC-1015-NSS 3-RC-1015-NSS-11 Pressurizer PORV Line 5B 2.626 -22.08 -624.36 1259.25 Cold PZR Compartment 142 3-RC-1015-NSS 3-RC-1015-NSS-12 Pressurizer PORV Line 5B 2.626 -15.92 -616.48 1259.25 Cold PZR Compartment 143 3-RC-1015-NSS 3-RC-1015-NSS-13 Pressurizer PORV Line 5B 2.626 -10.38 -609.39 1259.25 Cold PZR Compartment 144 3-RC-1O15-NSS 3-RC-1015-NSS-14 Pressurizer PORV Line 5B 2.626 -1.17 -597.6 1259.25 Cold PZR Compartment 145 3-RC-1015-NSS 3-RC-1015-NSS-15 Pressurizer PORV Line 5B 2.626 5.33 -596.8 1259.25 Cold PZR Compartment 146 3-RC-1015-NSS 3-RC-1015-NSS-16 Pressurizer PORV Line 5B 2.626 25.24 -612.36 1259.25 Cold PZR Compartment 147 3-RC-1106-BB1 3-RC-1106-B81-25 SI -Capped 7J 2.626 -278.44 -299.61 430.31 Cold SG Compartment 148 3-RC-1206-BB1 3-RC-1206-B81-28 SI -Capped 7J 2.626 -278.44 299.61 430.31 Cold SG Compartment 149 3-RC-1306-BB1 3-RC-1306-BB1-28 SI -Capped 7J 2.626 302.44 299.61 430.31 Cold SG Compartment 150 3-RC-1406-BB1 3-RC-1406-B81-25 SI -Capped 7J 2.626 302.44 -299.61 430.31 Cold SG Compartment 151 4-CV-1001-BB1 4-CV-1001-BB1-1 CV -RC Crossover-3 8B 3.438 204.13 243.01 372.31 Cold SG Compartment 152 4-CV-1001-BB1 4-CV-1001-BB1-2 CV -RC Crossover-3 8B 3.438 182.13 243.01 372.31 Cold SG Compartment 153 4-CV-1118-BB1 4-CV-1118-BB1-1 CV -RC Coldleg 1 8B 3.438 -328 -91.56 507 Cold SG Compartment 154 4-CV-1118-BB1 4-CV-1118-BB1-2 CV -RC Coldleg 1 86 3.438 -269 -91.56 507 Cold SG Compartment 155 4-CV-1120-BB1 4-CV-1120-1B1-1 CV -RC Coldleg 3 86 3.438 181.59 196.84 522 Cold SG Compartment 156 4-CV-1120-BB1 4-CV-1120-881-2 CV -RC Coldleg 3 8B 3.438 190.07 205.33 522 Cold SG Compartment 157 4-RC-1000-BB1 4-RC-1000-BB1-1 Pressurizer Spray 5C 3.438 82.44 -594.19 984 Cold PZR Compartment 158 4-RC-1000-BB1 4-RC-1000-BB1-2 Pressurizer Spray 5C 3.438 91.81 -594.19 984 Cold PZR Compartment 159 4-RC-1000-BB1 4-RC-1000-BB1-3 Pressurizer Spray 5C 3.438 97.81 -594.19 990 Cold PZR Compartment 160 4-RC-1000-BB1 4-RC-1000-BB1-4 Pressurizer Spray 5C 3.438 97.81 -594.19 1023 Cold PZR Compartment 161 4-RC-1000-BB1 4-RC-1000-BB1-5 Pressurizer Spray SC 3.438 100.64 -597.02 1029 Cold PZR Compartment 162 4-RC-1000-BB1 4-RC-1000-BB1-6 Pressurizer Spray 5C 3.438 105.17 -601.55 1029 Cold PZR Compartment Page 148 of 260 South Texas Project Risk-Informed GSI-191 Evaluation Volume 3: CASA Grande Analysis RI-GS1191-V03 Revision 1 No. Line Number Location Name System Category Pipe ID X Y Z Side Compartment 163 4-RC-1000-BB1 4-RC-1000-8B1-7 Pressurizer Spray 5C 3.438 108 -608.38 1029 Cold PZR Compartment 164 4-RC-1000-BB1 4-RC-1000-BB1-8 Pressurizer Spray 5C 3.438 108 -636 1029 Cold PZR Compartment 165 4-RC-1003-BB1 4-RC-1003-B81-1 Pressurizer Spray 5C 3.438 108 -635 984 Cold PZR Compartment 166 4-RC-1003-BB1 4-RC-1003-BB1-2 Pressurizer Spray 5C 3.438 108 -642 984 Cold PZR Compartment 167 4-RC-1003-BB1 4-RC-1003-BB1-3 Pressurizer Spray 5C 3.438 108 -648 990 Cold PZR Compartment 168 4-RC-1003-BB1 4-RC-1003-BB1-4 Pressurizer Spray 5C 3.438 108 -648 1008 Cold PZR Compartment 169 4-RC-1123-BB1 4-RC-1123-BB1-1 Pressurizer Spray 51* 3.438 -252.54 -190.08 545.88 Cold SG Compartment 170 4-RC-1123-BB1 4-RC-1123-BB1-2 Pressurizer Spray 5C 3.438 -252.54 -190.08 708 Cold SG Compartment 171 4-RC-1123-BB1 4-RC-1123-BB1-3 Pressurizer Spray 5C 3.438 -252.54 -190.08 723 Cold SG Compartment 172 4-RC-1123-BB1 4-RC-1123-BB1-4 Pressurizer Spray 5C 3.438 -244.06 -198.57 735 Cold SG Compartment 173 4-RC-1123-BB1 4-RC-1123-B81-5 Pressurizer Spray 5C 3.438 -211.95 -230.67 735 Cold SG Compartment 174 4-RC-1123-BB1 4-RC-1123-BB1-6 Pressurizer Spray 5C 3.438 -203.47 -234.19 735 Cold SG Compartment 175 4-RC-1123-BB1 4-RC-1123-BB1-7 Pressurizer Spray 5C 3.438 -30.19 -234.19 735 Cold SG Compartment 176 4-RC-1123-BBI 4-RC-1123-BB1-8 Pressurizer Spray 5C 3.438 -18.19 -246.27 735 Cold SG Compartment 177 4-RC-1123-BB1 4-RC-1123-BB1-9 Pressurizer Spray 5C 3.438 -18.19 -372.19 735 Cold SG Compartment 178 4-RC-1123-BB1 4-RC-1123-BB1-10 Pressurizer Spray 5C 3.438 -18.19 -504.19 735 Cold SG Compartment 179 4-RC-1123-BB1 4-RC-1123-BB1-11 Pressurizer Spray 5C 3.438 -18.19 -516.19 747 Cold SG Compartment 180 4-RC-1123-BB1 4-RC-1123-BB1-12 Pressurizer Spray 5C 3.438 -18.19 -516.19 879 Cold SG Compartment 181 4-RC-1123-BB1 4-RC-1123-BB1-13 Pressurizer Spray 5C 3.438 -6.19 -516.19 891 Cold SG Compartment 182 4-RC-1123-BB1 4-RC-1123-BB1-14 Pressurizer Spray 5C 3.438 38.99 -516.19 891 Cold SG Compartment 183 4-RC-1123-BB1 4-RC-1123-BB1-15 Pressurizer Spray 5C 3.438 50.81 -528.19 891 Cold SG Compartment 184 4-RC-1123-BB1 4-RC-1123-B81-16 Pressurizer Spray 5C 3.438 50.81 -588.19 891 Cold PZR Compartment 185 4-RC-1123-BB1 4-RC-1123-BB1-17 Pressurizer Spray 5C 3.438 50.81 -594.19 897 Cold PZR Compartment 186 4-RC-1123-BB1 4-RC-1123-BB1-18 Pressurizer Spray 5C 3.438 50.81 -594.19 978 Cold PZR Compartment 187 4-RC-1123-BB1 4-RC-1123-BB1-19 Pressurizer Spray 5C 3.438 56.81 -594.19 984 Cold PZR Compartment 188 4-RC-1123-BB1 4-RC-1123-BB1-20 Pressurizer Spray 5C 3.438 75.62 -594.19 984 Cold PZR Compartment 189 4-RC-1126-BB1 4-RC-1126-BB1-1 CV -RC Coldleg 1 88 3.438 -255 -91.56 507 Cold SG Compartment 190 4-RC-1126-BB1 4-RC-1126-BB1-2 CV -RC Coldleg I 8B 3.438 -228 -91.56 507 Cold SG Compartment 191 4-RC-1126-BB1 4-RC-1126-BB1-3 CV -RC Coldleg 1 8B 3.438 -222 -91.56 513 Cold SG Compartment 192 4-RC-1126-BB1 4-RC-1126-BB1-4 CV -RC Coldleg 1 8B 3.438 -222 -91.56 516 Cold SG Compartment 193 4-RC-1126-BB1 4-RC-1126-BB1-5 CV -RC Coldleg 1 88 3.438 -217.76 -95.8 522 Cold SG Compartment 194 4-RC-1126-BB1 4-RC-1126-BB1-6 CV -RC Coldleg 1 8E 3.438 -205.01 -108.55 522 Cold SG Compartment 195 4-RC-1320-BB1 4-RC-1320-BB1-1 CV -RC Crossover-3 8F 3.438 295.13 306.07 381.31 Cold SG Compartment 196 4-RC-1320-BB1 4-RC-1320-BB1-2 CV -RC Crossover-3 8D 3.438 295.13 306.07 377.31 Cold SG Compartment 197 4-RC-1320-B81 4-RC-1320-BB1-3 CV -RC Crossover-3 8D 3.438 290.13 306.07 372.31 Cold SG Compartment 198 4-RC-1320-BB1 4-RC-1320-BB1-4 CV -RC Crossover-3 8D 3.438 246.13 306.07 372.31 Cold SG Compartment 199 4-RC-1320-BB1 4-RC-1320-BB1-5 CV -RC Crossover-3 8D 3.438 241.13 301.07 372.31 Cold SG Compartment 200 4-RC-1320-BB1 4-RC-1320-BB1-6 CV -RC Crossover-3 8D 3.438 241.13 291.07 372.31 Cold SG Compartment 201 4-RC-1320-BB1 4-RC-1320-BB1-7 CV -RC Crossover-3 8D 3.438 241.13 285.07 372.31 Cold SG Compartment 202 4-RC-1320-BB1 4-RC-1320-BB1-8 CV -RC Crossover-3 8B 3.438 241.13 274.01 372.31 Cold SG Compartment 203 4-RC-1320-BB1 4-RC-1320-BB1-9 CV -RC Crossover-3 8B 3.438 241.13 258.01 372.31 Cold SG Compartment Page 149 of 260 South Texas Project Risk-Informed GSI-191 Evaluation Volume 3: CASA Grande Analysis RI-GSI191-V03 Revision 1 No. Line Number Location Name System Category Pipe ID X Y Z Side Compartment 204 4-RC-1320-BB1 4-RC-1320-BB1-10 CV -RC Crossover-3 8B 3.438 241.13 248.01 372.31 Cold SG Compartment 205 4-RC-1320-BB1 4-RC-1320-BB1-11 CV -RC Crossover-3 8B 3.438 236.13 243.01 372.31 Cold SG Compartment 206 4-RC-1320-BB1 4-RC-1320-BB1-12 CV -RC Crossover-3 8B 3.438 220.13 243.01 372.31 Cold SG Compartment 207 4-RC-1323-BB1 4-RC-1323-BB1-1 CV -RC Coldleg 3 8B 3.438 171.7 186.93 522 Cold SG Compartment 208 4-RC-1323-BB1 4-RC-1323-BB1-2 CV -RC Coldleg 3 8B 3.438 164.64 179.85 522 Cold SG Compartment 209 4-RC-1323-BB1 4-RC-1323-BB1-3 CV -RC Coldleg 3 8B 3.438 164.65 172.78 522 Cold SG Compartment 210 4-RC-1323-BB1 4-RC-1323-BB1-4 CV -RC Coldleg 3 8E 3.438 195.67 141.82 522 Cold SG Compartment 211 4-RC-1420-BB1 4-RC-1420-BB1-1 SI 71 3.438 273.56 -187.1 548 Cold SG Compartment 212 4-RC-1422-BB1 4-RC-1422-BB1-1 Pressurizer Spray 51* 3.438 252.15 -188.74 538.31 Cold SG Compartment 213 4-RC-1422-BB1 4-RC-1422-BB1-2 Pressurizer Spray 5C 3.438 249 -191.89 542.76 Cold SG Compartment 214 4-RC-1422-BB1 4-RC-1422-BB1-3 Pressurizer Spray 5C 3.438 250.24 -199.13 547 Cold SG Compartment 215 4-RC-1422-BB1 4-RC-1422-BB1-4 Pressurizer Spray 5C 3.438 259.44 -208.33 547 Cold SG Compartment 216 4-RC-1422-BB1 4-RC-1422-BB1-5 Pressurizer Spray 5C 3.438 263.68 -212.57 553 Cold SG Compartment 217 4-RC-1422-BB1 4-RC-1422-BB1-6 Pressurizer Spray 5C 3.438 263.68 -212.57 729 Cold SG Compartment 218 4-RC-1422-BB1 4-RC-1422-BB1-7 Pressurizer Spray 5C 3.438 263.68 -218.57 735 Cold SG Compartment 219 4-RC-1422-BB1 4-RC-1422-BB1-8 Pressurizer Spray 5C 3.438 263.68 -228 735 Cold SG Compartment 220 4-RC-1422-BB1 4-RC-1422-BB1-9 Pressurizer Spray SC 3.438 257.68 -234 735 Cold SG Compartment 221 4-RC-1422-BB1 4-RC-1422-BB1-10 Pressurizer Spray SC 3.438 57 -234 735 Cold SG Compartment 222 4-RC-1422-BB1 4-RC-1422-BB1-11 Pressurizer Spray 5C 3.438 45 -246 735 Cold SG Compartment 223 4-RC-1422-BB1 4-RC-1422-BB1-12 Pressurizer Spray SC 3.438 45 -384 735 Cold SG Compartment 224 4-RC-1422-BB1 4-RC-1422-BB1-13 Pressurizer Spray 5C 3.438 45 -504.07 735 Cold SG Compartment 225 4-RC-1422-BB1 4-RC-1422-BB1-14 Pressurizer Spray 5C 3.438 57 -516 735 Cold SG Compartment 226 4-RC-1422-BB1 4-RC-1422-BB1-15 Pressurizer Spray 5C 3.438 96.03 -516 735 Cold SG Compartment 227 4-RC-1422-BB1 4-RC-1422-BB1-16 Pressurizer Spray 5C 3.438 108 -516 747 Cold SG Compartment 228 4-RC-1422-BB1 4-RC-1422-BB1-17 Pressurizer Spray 5C 3.438 108 -516 879 Cold SG Compartment 229 4-RC-1422-BB1 4-RC-1422-BB1-18 Pressurizer Spray 5C 3.438 108 -528 891 Cold SG Compartment 230 4-RC-1422-BB1 4-RC-1422-BB1-19 Pressurizer Spray 5C 3.438 108 -582 891 Cold SG Compartment 231 4-RC-1422-BB1 4-RC-1422-BB1-20 Pressurizer Spray 5C 3.438 108 -594 903 Cold PZR Compartment 232 4-RC-1422-BB1 4-RC-1422-8B1-21 Pressurizer Spray SC 3.438 108 -594 972 Cold PZR Compartment 233 4-RC-1422-BB1 4-RC-1422-BB1-22 Pressurizer Spray 5C 3.438 108 -606 984 Cold PZR Compartment 234 4-RC-1422-BB1 4-RC-1422-BB1-23 Pressurizer Spray 5C 3.438 108 -621.38 984 Cold PZR Compartment 235 6-RC-1003-BB1 6-RC-1003-BB1-1 Pressurizer Spray 5E 5.189 108 -648 1017 Cold PZR Compartment 236 6-RC-1003-BB1 6-RC-1003-BB1-2 Pressurizer Spray 5E 5.189 108 -648 1025 Cold PZR Compartment 237 6-RC-1003-BB1 6-RC-1003-BB1-3 Pressurizer Spray 5E 5.189 108 -648 1033 Cold PZR Compartment 238 6-RC-1003-BB1 6-RC-1003-BB1-4 Pressurizer Spray 5A 5.189 108 -648 1058 Cold PZR Compartment 239 6-RC-1003-BB1 6-RC-1003-BB1-5 Pressurizer Spray 5A 5.189 108 -648 1066 Cold PZR Compartment 240 6-RC-1003-BB1 6-RC-1003-8B1-6 Pressurizer Spray 5A 5.189 108 -648 1083 Cold PZR Compartment 241 6-RC-1003-BB1 6-RC-1003-B81-7 Pressurizer Spray 5A 5.189 97.58 -642.05 1095 Cold PZR Compartment 242 6-RC-1003-BB1 6-RC-1003-B81-8 Pressurizer Spray 5A 5.189 76.42 -629.95 1095 Cold PZR Compartment 243 6-RC-1003-BB1 6-RC-1003-BB1-9 Pressurizer Spray 5A 5.189 66 -624 1107 Cold PZR Compartment 244 6-RC-1003-BB1 6-RC-1003-BB1-9A Pressurizer Spray 5A 5.189 66 -624 1128 Cold PZR Compartment Page 150 of 260 South Texas Project Risk-Informed GSI-191 Evaluation Volume 3: CASA Grande Analysis RI-GSI191-V03 Revision 1 No. Line Number Location Name System Category Pipe ID X Y Z Side Compartment 245 6-RC-1003-BB1 6-RC-1003-B81-9B Pressurizer Spray 5A 5.189 66 -624 1149 Cold PZR Compartment 246 6-RC-1003-BB1 6-RC-1003-861-10 Pressurizer Spray 5A 5.189 66 -624 1251 Cold PZR Compartment 247 6-RC-1003-B61 6-RC-1003-BB1-11 Pressurizer Spray 5A 5.189 57.51 -632.49 1263 Cold PZR Compartment 248 6-RC-1003-BB1 6-RC-1003-BB1-11A Pressurizer Spray 5A 5.189 49.03 -640.97 1263 Cold PZR Compartment 249 6-RC-1003-BB1 6-RC-1003-881-118 Pressurizer Spray 5A 5.189 43.37 -646.63 1263 Cold PZR Compartment 250 6-RC-1003-BB1 6-RC-1003-BB1-12 Pressurizer Spray 5A 5.189 20.49 -669.51 1263 Cold PZR Compartment 251 6-RC-1003-BB1 6-RC-1003-881-13 Pressurizer Spray 5A 5.189 12 -678 1251 Cold PZR Compartment 252 6-RC-1003-BB1 6-RC-1003-BB1-13A Pressurizer Spray 5A 5.189 12 -678 1236.5 Cold PZR Compartment 253 6-RC-1003-BB1 6-RC-1003-BB1-14 Pressurizer Spray 5H* 5.189 12 -678 1222 Cold PZR Compartment 254 6-RC-1003-BB1 6-RC-1003-BB1-PRZ-1-N2-SE Pressurizer Spray 5F 5.189 12 -678 1222.5 Cold PZR Compartment 255 6-RC-1004-NSS 6-RC-1004-NSS-1 Pressurizer SRV Line 5H* 5.189 5.95 -721.01 1202.7 Cold PZR Compartment 256 6-RC-1004-NSS 6-RC-1004-NSS-2 Pressurizer SRV Line 5E 5.189 5.59 -723.61 1208.62 Cold PZR Compartment 257 6-RC-1004-NSS 6-RC-1004-NSS-3 Pressurizer SRV Line 5E 5.189 5.59 -723.61 1227.28 Cold PZR Compartment 258 6-RC-1004-NSS 6-RC-1004-NSS-4 Pressurizer SRV Line 5E 5.189 20.1 -711 1227.27 Cold PZR Compartment 259 6-RC-1004-NSS 6-RC-1004-NSS-5 Pressurizer SRV Line 5A 5.189 20.1 -711 1222.1 Cold PZR Compartment 260 6-RC-1004-NSS 6-RC-1004-NSS-6 Pressurizer SRV Line 5A 5.189 23.31 -729.95 1222.1 Cold PZR Compartment 261 6-RC-1004-NSS 6-RC-1004-NSS-7 Pressurizer SRV Line 5A 5.189 23.31 -729.95 1232.5 Cold PZR Compartment 262 6-RC-1004-NSS 6-RC-1004-NSS-PRZ-1-N3-SE Pressurizer SRV Line 5F 5.189 5.95 -721.01 1202.7 Cold PZR Compartment 263 6-RC-1009-NSS 6-RC-1009-NSS-1 Pressurizer SRV Line 5H* 5.189 49.17 -702.14 1206.45 Cold PZR Compartment 264 6-RC-1009-NSS 6-RC-1009-NSS-2 Pressurizer SRV Line 5E 5.189 51.2 -703.46 1212.19 Cold PZR Compartment 265 6-RC-1009-NSS 6-RC-1009-NSS-3 Pressurizer SRV Line 5E 5.189 51.2 -703.46 1232.45 Cold PZR Compartment 266 6-RC-1009-NSS 6-RC-1009-NSS-4 Pressurizer SRV Line 5E 5.189 48.64 -686.29 1232.47 Cold PZR Compartment 267 6-RC-1009-NSS 6-RC-1009-NSS-5 Pressurizer SRV Line 5A 5.189 48.64 -686.29 1220.3 Cold PZR Compartment 268 6-RC-1009-NSS 6-RC-1009-NSS-6 Pressurizer SRV Line 5A 5.189 53.56 -679.99 1212.3 Cold PZR Compartment 269 6-RC-1009-NSS 6-RC-1009-NSS-7 Pressurizer SRV Line 5A 5.189 59.03 -672.99 1212.3 Cold PZR Compartment 270 6-RC-1009-NSS 6-RC-1009-NSS-8 Pressurizer SRV Line 5A 5.189 63.95 -666.69 1220.3 Cold PZR Compartment 271 6-RC-1009-NSS 6-RC-1009-NSS-9 Pressurizer SRV Line 5A 5.189 63.95 -666.69 1232.3 Cold PZR Compartment 272 6-RC-1009-NSS 6-RC-1009-NSS-PRZ-1-N4C-SE Pressurizer SRV Line 5F 5.189 49.32 -702.24 1206.63 Cold PZR Compartment 273 6-RC-1012-NSS 6-RC-1012-NSS-1 Pressurizer SRV Line 5H* 5.189 49.79 -654.39 1205.31 Cold PZR Compartment 274 6-RC-1012-NSS 6-RC-1012-NSS-2 Pressurizer SRV Line 5E 5.189 51.78 -653.15 1210.97 Cold PZR Compartment 275 6-RC-1012-NSS 6-RC-1012-NSS-3 Pressurizer SRV Line 5E 5.189 51.78 -653.15 1216.43 Cold PZR Compartment 276 6-RC-1012-NSS 6-RC-1012-NSS-4 Pressurizer SRV Line 5E 5.189 47.03 -652.31 1223.77 Cold PZR Compartment 277 6-RC-1012-NSS 6-RC-1012-NSS-5 Pressurizer SRV Line 5E 5.189 8.75 -645.56 1240.59 Cold PZR Compartment 278 6-RC-1012-NSS 6-RC-1012-NSS-6 Pressurizer SRV Line 5E 5.189 5.62 -645.01 1241.25 Cold PZR Compartment 279 6-RC-1012-NSS 6-RC-1012-NSS-7 Pressurizer SRV Line 5A 5.189 -2.85 -643.51 1241.25 Cold PZR Compartment 280 6-RC-1012-NSS 6-RC-1012-NSS-8 Pressurizer SRV Line SA 5.189 -10.72 -642.13 1233.25 Cold PZR Compartment 281 6-RC-1012-NSS 6-RC-1012-NSS-9 Pressurizer SRV Line 5A 5.189 -10.72 -642.13 1222.53 Cold PZR Compartment 282 6-RC-1012-NSS 6-RC-1012-NSS-10 Pressurizer SRV Line 5A 5.189 0.69 -626.05 1222.52 Cold PZR Compartment 283 6-RC-1012-NSS 6-RC-1012-NSS-11 Pressurizer SRV Line 5A 5.189 0.69 -626.05 1225.38 Cold PZR Compartment 284 6-RC-1012-NSS 6-RC-1012-NSS-PRZ-1-N4B-SE Pressurizer SRV Line 5F 5.189 49.64 -654.48 1205.13 Cold PZR Compartment 285 6-RC-1015-NSS 6-RC-1015-NSS-1 Pressurizer PORV Line 5E 5.189 5.6 -635.02 1202.71 Cold PZR Compartment Page 151 of 260 South Texas Project Risk-Informed GSI-191 Evaluation Volume 3: CASA Grande Analysis RI-GSI191-V03 Revision 1 No. Line Number Location Name System Category Pipe ID X Y Z Side Compartment 286 6-RC-1015-NSS 6-RC-1015-NSS-2 Pressurizer PORV Line 5E 5.189 5.23 -632.42 1208.64 Cold PZR Compartment 287 6-RC-1015-NSS 6-RC-1015-NSS-3 Pressurizer PORV Line 5E 5.189 5.23 -632.42 1217.93 Cold PZR Compartment 288 6-RC-1015-NSS 6-RC-1015-NSS-4 Pressurizer PORV Line 5E 5.189 6.35 -640.34 1225.93 Cold PZR Compartment 289 6-RC-1015-NSS 6-RC-1015-NSS-5 Pressurizer PORV Line 5E 5.189 7.58 -649.1 1225.93 Cold PZR Compartment 290 6-RC-1015-NSS 6-RC-1015-NSS-6 Pressurizer PORV Line 5E 5.189 5.96 -655.14 1225.93 Cold PZR Compartment 291 6-RC-1015-NSS 6-RC-1015-NSS-7 Pressurizer PORV Line 5E 5.189 2.1 -660.08 1225.93 Cold PZR Compartment 292 6-RC-1015-NSS 6-RC-1015-NSS-8 Pressurizer PORV Line 5E 5.189 -2.84 -666.4 1233.93 Cold PZR Compartment 293 6-RC-1015-NSS 6-RC-1015-NSS-9 Pressurizer PORV Line 5E 5.189 -2.84 -666.4 1240.98 Cold PZR Compartment 294 6-RC-1015-NSS 6-RC-1015-NSS-10 Pressurizer PORV Line 5E 5.189 -6.91 -663.22 1248.46 Cold PZR Compartment 295 6-RC-1015-NSS 6-RC-1015-NSS-11 Pressurizer PORV Line 5E 5.189 -30.76 -644.59 1259.94 Cold PZR Compartment 296 6-RC-1015-NSS 6-RC-1015-NS5-12 Pressurizer PORV Line 5E 5.189 -38.88 -645.87 1262.06 Cold PZR Compartment 297 6-RC-1015-NSS 6-RC-1015-NSS-13 Pressurizer PORV Line 5E 5.189 -40.72 -648.23 1262.06 Cold PZR Compartment 298 6-RC-1015-NSS 6-RC-1015-NSS-14 Pressurizer PORV Line 5E 5.189 -31.49 -636.41 1262.06 Cold PZR Compartment 299 6-RC-1O15-NSS 6-RC-1015-NSS-15 Pressurizer PORV Line 5E 5.189 -29.64 -634.05 1262.06 Cold PZR Compartment 300 6-SI-1108-BB1 6-SI-1108-BB1-1 SI 7H 5.189 -394.51 -458.32 483 Hot Annulus 301 6-SI-1108-BB1 6-S1-1108-BB1-2 SI 7H 5.189 -390.98 -461.85 483 Hot Annulus 302 6-SI-1108-BB1 6-SI-1108-BB1-3 SI 7H 5.189 -376.83 -461.85 483 Hot Annulus 303 6-SI-1108-BB1 6-51-1108-BB1-4 SI 7H 5.189 -337.24 -422.26 483 Hot SG Compartment 304 6-SI-1111-BB1 6-SI-1111-BB1-1 SI 7H 5.189 -401.01 -237.72 231.01 Cold Below SG Compartment 305 6-SI-1111-BB1 6-51-1111-BB1-2 SI 7H 5.189 -401.01 -230.38 231.01 Cold Below SG Compartment 306 6-S1-1208-BB1 6-S1-1208-BB1-1 SI 7H 5.189 -374.64 478.19 483 Hot Annulus 307 6-SI-1208-BB1 6-S5-1208-BB1-2 SI 7H 5.189 -378.18 474.65 483 Hot Annulus 308 6-SI-1208-8B1 6-S1-1208-BB1-3 SI 7H 5.189 -378.18 460.51 483 Hot Annulus 309 6-SI-1208-BB1 6-S1-1208-BB1-4 51 7H 5.189 -338.58 420.91 483 Hot SG Compartment 310 6-S1-1211-BB1 6-S1-1211-BB1-1 S5 7H 5.189 -392.04 236.38 231.01 Cold Below SG Compartment 311 6-S1-1211-B81 6-S1-1211-BB1-2 Sl 7H 5.189 -392.04 229.38 231.01 Cold Below SG Compartment 312 6-SI-1308-BB1 6-S1-1308-BB1-1 RH 7H 5.189 514 146.37 230.92 Cold RHR Compartment 313 6-SI-1308-BB1 6-S1-1308-8B1-2 RH 7H 5.189 454.5 146.37 230.92 Cold Below SG Compartment 314 6-S1-1308-B81 6-SI-1308-BB1-3 RH 7H 5.189 446.5 154.37 230.92 Cold Below SG Compartment 315 6-SI-1308-BB1 6-SI-1308-BB1-4 RH 7H 5.189 446.5 164.37 230.92 Cold Below 5G Compartment 316 6-SI-1327-BB1 6-S1-1327-B81-1 SI 7H 5.189 407.93 305.38 491.92 Hot SG Compartment 317 6-S1-1327-BB1 6-SI-1327-BB1-2 SI 7H 5.189 407.9 315.13 491.92 Hot SG Compartment 318 6-SI-1327-BB1 6-S1-1327-BB1-3 SI 7H 5.189 404.5 323.62 491.92 Hot SG Compartment 319 6-SI-1327-BB1 6-S1-1327-BB1-4 Si 7H 5.189 371.97 356.14 491.92 Hot SG Compartment 320 6-SI-1327-BB1 6-S1-1327-B81-5 SI 7H 5.189 357.12 370.99 491.92 Hot SG Compartment 321 6-SI-1327-BB1 6-S1-1327-BB1-6 SI 7H 5.189 357.12 379.48 491.92 Hot SG Compartment 322 6-SI-1327-B81 6-S1-1327-BB1-7 SI 7H 5.189 363.49 385.84 491.92 Hot SG Compartment 323 8-RC-1114-BBI 8-RC-1114-BB1-1 SI 7B 6.813 -148.4 -233.45 483 Hot SG Compartment 324 8-RC-1114-BB1 8-RC-1114-B81-2 SI 7B 6.813 -134.97 -220.01 483 Hot SG Compartment 325 8-RC-1114-BB1 8-RC-1114-BB1-3 SI 76 6.813 -126.48 -211.52 495 Hot SG Compartment 326 8-RC-1114-B81 8-RC-1114-BB1-4 SI 7G 6.813 -126.48 -211.52 510 Hot SG Compartment Page 152 of 260 South Texas Project Risk-Informed GSI-191 Evaluation Volume 3: CASA Grande Analysis RI-GSI191-V03 Revision 1 No. Line Number Location Name System Category Pipe ID X Y Z Side Compartment 327 8-RC-1114-BB1 8-RC-1114-BB1-5 51 7G 6.813 -115.35 -216.02 522 Hot SG Compartment 328 8-RC-1114-BB1 8-RC-1114-BB1-6 SI 7G 6.813 -107.94 -219.02 522 Hot SG Compartment 329 8-RC-1214-BB1 8-RC-1214-BB1-1 SI 7B 6.813 -149.63 231.95 483 Hot SG Compartment 330 8-RC-1214-BB1 8-RC-1214-BB1-2 SI 7B 6.813 -136.91 219.23 483 Hot SG Compartment 331 8-RC-1214-BB1 8-RC-1214-BB1-3 SI 7B 6.813 -128.42 210.74 495 Hot SG Compartment 332 8-RC-1214-BB1 8-RC-1214-BB1-4 SI 7G 6.813 -128.42 210.74 510 Hot SG Compartment 333 8-RC-1214-BB1 8-RC-1214-BB1-5 51 7G 6.813 -117.29 215.24 522 Hot SG Compartment 334 8-RC-1214-BB1 8-RC-1214-BB1-6 SI 7G 6.813 -109.12 218.54 522 Hot SG Compartment 335 8-RC-1324-BB1 8-RC-1324-BB1-1 SI 7B 6.813 169.39 227.71 492 Hot SG Compartment 336 8-RC-1324-BB1 8-RC-1324-BB1-2 SI 78 6.813 160.91 219.23 492 Hot SG Compartment 337 8-RC-1324-BB1 8-RC-1324-BB1-3 SI 78 6.813 152.42 210.74 504 Hot SG Compartment 338 8-RC-1324-BB1 8-RC-1324-BB1-4 SI 7G 6.813 152.42 210.74 510 Hot SG Compartment 339 8-RC-1324-BB1 8-RC-1324-BB1-5 SI 7G 6.813 141.31 215.23 522 Hot SG Compartment 340 8-RC-1324-BB1 8-RC-1324-BB1-6 SI 7G 6.813 133.12 218.54 522 Hot SG Compartment 341 8-RH-1108-BB1 8-RH-1108-BB1-1 RH 7G 6.813 -438 -221.37 231.01 Cold Below SG Compartment 342 8-RH-1108-BB1 8-RH-1108-BB1-2 RH 7G 6.813 -422.5 -221.37 231.01 Cold Below SG Compartment 343 8-RH-1112-BB1 8-RH-1112-BB1-1 RH 7G 6.813 -375.82 -358.25 483.01 Hot SG Compartment 344 8-RH-1112-BB1 8-RH-1112-BB1-1A RH 7G 6.813 -333.39 -400.68 483.01 Hot SG Compartment 345 8-RH-1112-BB1 8-RH-1112-BB1-2 RH 7G 6.813 -327.03 -407.04 483.01 Hot SG Compartment 346 8-RH-1208-BB1 8-RH-1208-BB1-1 RH 7G 6.813 -438 221.38 231.01 Cold Below SG Compartment 347 8-RH-1208-BB1 8-RH-1208-BB1-2 RH 7G 6.813 -422.5 221.38 231.01 Cold Below SG Compartment 348 8-RH-1212-BB1 8-RH-1212-BB1-1 RH 7G 6.813 -367.47 369.22 483.01 Hot SG Compartment 349 8-RH-1212-BB1 8-RH-1212-BB1-2 RH 7G 6.813 -331.42 405.27 483.01 Hot SG Compartment 350 8-RH-1308-BB1 8-RH-1308-BB1-1 RH 7G 6.813 553 170.12 230.92 Cold RHR Compartment 351 8-RH-1308-BB1 8-RH-1308-BB1-2 RH 7G 6.813 516 170.12 230.92 Cold RHR Compartment 352 8-RH-1315-BB1 8-RH-1315-BB1-1 RH 7G 6.813 387.53 370.28 491.92 Hot SG Compartment 353 8-SI-1108-BB1 8-SI-1108-BB1-1 SI 7G 6.813 -337.24 -422.26 483 Hot SG Compartment 354 8-SI-1108-BB1 8-SI-1108-BB1-2 SI 7G 6.813 -328.77 -413.79 483 Hot SG Compartment 355 8-SI-1108-BB1 8-SI-1108-BB1-3 SI 7G 6.813 -320.28 -405.3 483 Hot SG Compartment 356 8-SI-1108-BB1 8-SI-1108-BB1-4 SI 7G 6.813 -177.96 -262.98 483 Hot SG Compartment 357 8-SI-1108-BB1 8-51-1108-8B1-5 SI 7C 6.813 -165.23 -250.25 483 Hot SG Compartment 358 8-51-1208-BB1 8-S1-1208-BB1-1 SI 7G 6.813 -338.58 420.91 483 Hot SG Compartment 359 8-S1-1208-BB1 8-SI-1208-BB1-2 SI 7G 6.813 -332.83 415.17 483 Hot SG Compartment 360 8-51-1208-BB1 8-SI-1208-BB1-3 SI 7G 6.813 -321.52 403.85 483 Hot SG Compartment 361 8-SI-1208-BB1 8-S1-1208-BB1-3A Sl 7G 6.813 -177.2 259.54 483 Hot SG Compartment 362 8-51-1208-BB1 8-SI-1208-BB1-4 SI 7C 6.813 -163.06 245.4 483 Hot 5G Compartment 363 8-SI-1327-BB1 8-S1-1327-BB1-1 Sl 7G 6.813 371.97 385.84 491.92 Hot SG Compartment 364 8-S1-1327-BB1 8-S1-1327-BB1-2 SI 7G 6.813 363.49 394.33 491.92 Hot SG Compartment 365 8-SI-1327-BB1 8-S1-1327-BB1-3 SI 7G 6.813 358.23 399.58 491.92 Hot SG Compartment 366 8-SI-1327-B81 8-51-1327-881-4 SI 7G 6.813 349.75 408.07 503.92 Hot SG Compartment 367 8-SI-1327-B81 8-S1-1327-881-5 SI 7G 6.813 349.75 408.07 528 Hot SG Compartment Page 153 of 260 South Texas Project Risk-Informed GSI-191 Evaluation Volume 3: CASA Grande Analysis RI-GSI191-V03 Revision 1 No. Une Number Location Name System Category Pipe ID X Y Z Side Compartment 368 8-Sl-1327-BB1 8-SI-1327-BB1-6 SI 7G 6.813 341.26 399.58 540 Hot SG Compartment 369 8-S1-1327-BB1 8-S1-1327-BB1-7 SI 7G 6.813 329.95 388.27 540 Hot SG Compartment 370 8-S1-1327-BB1 8-SI-1327-BB1-8 SI 7G 6.813 321.46 379.78 528 Hot SG Compartment 371 8-S1-1327-BB1 8-SI-1327-BB1-9 SI 7G 6.813 321.46 379.78 504 Hot SG Compartment 372 8-SI-1327-BB1 8-S1-1327-BB1-10 SI 7G 6.813 312.98 371.3 492 Hot SG Compartment 373 8-Sl-1327-BB1 8-Sl-1327-BB1-11 SI 7C 6.813 192.46 250.78 492 Hot SG Compartment 374 10-RH-1108-8B1 10-RH-1108-BB1-1 RH 7F 8.5 -422.5 -221.38 231.01 Cold Below SG Compartment 375 10-RH-1108-BB1 10-RH-1108-BB1-1A RH 7F 8.5 -410.33 -221.38 231.01 Cold Below SG Compartment 376 10-RH-1108-BB1 10-RH-1108-BB1-2 RH 7F 8.5 -404.08 -221.38 231.01 Cold Below SG Compartment 377 10-RH-1108-BB1 10-RH-1108-BB1-3 RH 7F 8.5 -386.08 -221.38 231.01 Cold Below SG Compartment 378 10-RH-1108-BB1 10-RH-1108-B81-4 RH 7F 8.5 -349.7 -221.38 231.01 Cold Below SG Compartment 379 10-RH-1108-BB1 10-RH-1108-BB1-5 RH 7F 8.5 -333.7 -221.38 247.01 Cold Below SG Compartment 380 10-RH-1108-BB1 10-RH-1108-BB1-6 RH 7F 8.5 -333,7 -221.38 257.01 Cold Below SG Compartment 381 10-RH-1108-BB1 10-RH-1108-BB1-7 RH 7F 8.5 -333.7 -237.38 273.01 Cold Below SG Compartment 382 10-RH-1108-BB1 10-RH-1108-BB1-8 RH 7F 8.5 -333.7 -368.92 273.01 Cold Below SG Compartment 383 10-RH-1108-BB1 10-RH-1108-BB1-9 RH 7F 8.5 -338.39 -380.23 273.01 Cold Below SG Compartment 384 10-RH-1108-BB1 10-RH-1108-BB1-10 RH 7F 8.5 -342.19 -384.03 273.01 Cold Below SG Compartment 385 10-RH-1208-BB1 10-RH-1208-BB1-1 RH 7F 8.5 -422.5 221.38 231.01 Cold Below SG Compartment 386 10-RH-1208-BB1 10-RH-1208-BB1-2 RH 7F 8.5 -407.7 221.38 231.01 Cold Below SG Compartment 387 10-RH-1208-BB1 10-RH-1208-BB1-3 RH 7F 8.5 -395.7 221.38 231.01 Cold Below SG Compartment 388 10-RH-1208-BB1 10-RH-1208-BB1-4 RH 7F 8.5 -349.7 221.38 231.01 Cold Below SG Compartment 389 10-RH-1208-BB1 10-RH-1208-BB1-5 RH 7F 8.5 -333.7 221.38 247.01 Cold Below SG Compartment 390 10-RH-1208-BB1 10-RH-1208-BB1-6 RH 7F 8.5 -333.7 221.38 257.01 Cold Below SG Compartment 391 10-RH-1208-BB1 10-RH-1208-BB1-7 RH 7F 8.5 -333.7 237.38 273.01 Cold Below SG Compartment 392 10-RH-1208-BB1 10-RH-1208-BB1-8 RH 7F 8.5 -333.7 327.46 273.01 Cold Below SG Compartment 393 10-RH-1208-BB1 10-RH-1208-BB1-9 RH 7F 8.5 -333.7 352.87 273.01 Cold Below SG Compartment 394 10-RH-1208-BB1 10-RH-1208-BB1-10 RH 7F 8.5 -338.39 364.09 273.01 Cold Below SG Compartment 395 10-RH-1208-BB1 10-RH-1208-BB1-11 RH 7F 8.5 -346.46 372.16 273.01 Cold Below SG Compartment 396 10-RH-1308-BB1 10-RH-1308-BB1-1 RH 7F 8.5 510 170.12 230.92 Cold RHR Compartment 397 10-RH-1308-BB1 10-RH-1308-BB1-2 RH 7F 8.5 455.5 170.12 230.92 Cold Below SG Compartment 398 10-RH-1308-BB1 10-RH-1308-BB1-3 RH 7F 8.5 437.5 170.12 230.92 Cold Below SG Compartment 399 10-RH-1308-BB1 10-RH-1308-BB1-4 RH 7F 8.5 433 170.12 230.92 Cold Below SG Compartment 400 10-RH-1308-BB1 10-RH-1308-BB1-5 RH 7F 8.5 417 186.12 230.92 Cold Below SG Compartment 401 10-RH-1308-BB1 10-RH-1308-BB1-6 RH 7F 8.5 417 331.73 230.92 Cold Below SG Compartment 402 10-RH-1308-BB1 10-RH-1308-BB1-7 RH 7F 8.5 401 347.73 230.92 Cold Below SG Compartment 403 10-RH-1308-BB1 10-RH-1308-BB1-8 RH 7F 8.5 345 347.73 230.92 Cold Below SG Compartment 404 12-RC-1112-BB1 12-RC-1112-BB1-1 RHR-Suction 7E 10.126 -63.57 -236.94 503.31 Hot SG Compartment 405 12-RC-1112-BB1 12-RC-1112-BB1-2 RHR-Suction 7A 10.126 -53.99 -240.81 492.97 Hot SG Compartment 406 12-RC-1112-BB1 12-RC-1112-BB1-3 RHR-Suction 7A 10.126 -49.64 -242.57 481.66 Hot SG Compartment 407 12-RC-1112-BB1 12-RC-1112-BB1-4 RHR-Suction 7A 10.126 -49.64 -242.57 472.04 Hot SG Compartment 408 12-RC-1112-BB1 12-RC-1112-881-5 RHR-Suction 7A 10.126 -38.33 -253.88 456.04 Hot SG Compartment Page 154 of 260 South Texas Project Risk-Informed GSI-191 Evaluation Volume 3: CASA Grande Analysis RI-GSI191-V03 Revision 1 No. Line Number Location Name System Category Pipe ID X Y Z Side Compartment 409 12-RC-1112-BB1 12-RC-1112-BB1-6 RHR-Suction 7A 10.126 -22.7 -269.51 456.04 Hot SG Compartment 410 12-RC-1112-BB1 12-RC-1112-BB1-7 RHR-Suction 7A 10.126 -18.02 -280.82 456.04 Hot SG Compartment 411 12-RC-1112-BB1 12-RC-1112-BB1-8 RHR-Suction 7A 10.126 -18.02 -438 456.04 Hot SG Compartment 412 12-RC-1112-BB1 12-RC-1112-BB1-9 RHR-Suction 7E 10.126 -18.02 -485 456.04 Hot SG Compartment 413 12-RC-1112-BB1 12-RC-1112-BBl-10 RHR-Suction 7E 10.126 -34.02 -501 456.04 Hot SG Compartment 414 12-RC-1112-BB1 12-RC-1112-BB1-11 RHR-Suction 7E 10.126 -78.02 -501 456.04 Hot SG Compartment 415 12-RC-1125-BB1 12-RC-1125-BBl-1 Sl-ACC-CL1 7N 10.126 -317.4 -428.18 273.02 Cold Below SG Compartment 416 12-RC-1125-BB1 12-RC-1125-BB1-2 SI-ACC-CL1 7N 10.126 -299.02 -446.57 273.02 Cold Below SG Compartment 417 12-RC-1125-BB1 12-RC-1125-BB1-3 SI-ACC-CL1 7N 10.126 -276.39 -446.57 273.02 Cold Below SG Compartment 418 12-RC-1125-BB1 12-RC-1125-BB1-4 SI-ACC-CL1 7N 10.126 -250.93 -421.11 273.02 Cold Below SG Compartment 419 12-RC-1125-BB1 12-RC-1125-BB1-5 Sl-ACC-CL1 7N 10.126 -250.93 -398.49 273.02 Cold Below SG Compartment 420 12-RC-1125-BB1 12-RC-1125-BB1-6 SI-ACC-CL1 7N 10.126 -293.63 -355.79 273.02 Cold Below SG Compartment 421 12-RC-1125-BB1 12-RC-1125-BB1-7 SI-ACC-CL1 7N 10.126 -304.94 -344.48 289.02 Cold Below SG Compartment 422 12-RC-1125-BB1 12-RC-1125-BB1-8 SI-ACC-CL1 7N 10.126 -304.94 -344.48 428.2 Cold SG Compartment 423 12-RC-1125-BB1 12-RC-1125-BB1-9 Sl-ACC-CL1 7N 10.126 -304.94 -344.48 532.2 Cold SG Compartment 424 12-RC-1125-BB1 12-RC-1125-BB1-10 SI-ACC-CL1 7N 10.126 -293.63 -333.17 548.2 Cold SG Compartment 425 12-RC-1125-BB1 12-RC-1125-BB1-11 SI-ACC-CL1 7N 10.126 -220.44 -259.98 548.2 Cold SG Compartment 426 12-RC-1125-BB1 12-RC-1125-BBl-12 Sl-ACC-CL1 7N 10.126 -215.3 -248.6 546.6 Cold SG Compartment 427 12-RC-1125-BB1 12-RC-1125-BB1-13 Sl-ACC-CL1 7N 10.126 -213.67 -194.95 533.24 Cold SG Compartment 428 12-RC-1212-BB1 12-RC-1212-BBl-1 RHR-Suction 7E 10.126 -60.71 238.07 500.23 Hot SG Compartment 429 12-RC-1212-BB1 12-RC-1212-BB1-2 RHR-Suction 7A 10.126 -52.9 241.23 491.81 Hot SG Compartment 430 12-RC-1212-BB1 12-RC-1212-BB1-3 RHR-Suction 7A 10.126 -49.64 242.54 483.33 Hot SG Compartment 431 12-RC-1212-BB1 12-RC-1212-BB1-4 RHR-Suction 7A 10.126 -49.64 242.54 468.01 Hot SG Compartment 432 12-RC-1212-BB1 12-RC-1212-BB1-5 RHR-Suction 7A 10.126 -41.17 251.02 456.01 Hot SG Compartment 433 12-RC-1212-BB1 12-RC-1212-BB1-6 RHR-Suction 7A 10.126 -21.52 270.67 456.01 Hot SG Compartment 434 12-RC-1212-BB1 12-RC-1212-BB1-7 RHR-Suction 7A 10.126 -18.01 279.07 456.01 Hot SG Compartment 435 12-RC-1212-BB1 12-RC-1212-BB1-8 RHR-Suction 7A 10.126 -18.01 414.99 456.01 Hot SG Compartment 436 12-RC-1221-BB1 12-RC-1221-BBl-1 SI-ACC-CL2 7N 10.126 -317.4 427.95 273.01 Cold Below SG Compartment 437 12-RC-1221-BB1 12-RC-1221-BB1-2 SI-ACC-CL2 7N 10.126 -299.05 446.3 273.01 Cold Below SG Compartment 438 12-RC-1221-BB1 12-RC-1221-BB1-3 SI-ACC-CL2 7N 10.126 -276.39 446.34 273.01 Cold Below SG Compartment 439 12-RC-1221-BB1 12-RC-1221-BB1-4 SI-ACC-CL2 7N 10.126 -250.93 420.88 273.01 Cold Below SG Compartment 440 12-RC-1221-BB1 12-RC-1221-BB1-5 SI-ACC-CL2 7N 10.126 -250.93 398.26 273.01 Cold Below SG Compartment 441 12-RC-1221-BB1 12-RC-1221-BB1-6 SI-ACC-CL2 7N 10.126 -293.63 355.56 273.01 Cold Below SG Compartment 442 12-RC-1221-BB1 12-RC-1221-BB1-7 SI-ACC-CL2 7N 10.126 -304.94 344.25 289.01 Cold Below SG Compartment 443 12-RC-1221-BB1 12-RC-1221-BB1-8 SI-ACC-CL2 7N 10.126 -304.94 344.25 410.59 Cold SG Compartment 444 12-RC-1221-BB1 12-RC-1221-BB1-9 SI-ACC-CL2 7N 10.126 -304.94 344.25 532.17 Cold SG Compartment 445 12-RC-1221-BB1 12-RC-1221-BB1-10 SI-ACC-CL2 7N 10.126 -293.63 332.94 548.17 Cold SG Compartment 446 12-RC-1221-BB1 12-RC-1221-BB1-11 SI-ACC-CL2 7N 10.126 -260.97 300.28 548.17 Cold SG Compartment 447 12-RC-1221-BB1 12-RC-1221-BB1-12 SI-ACC-CL2 7N 10.126 -221.77 261.08 548.17 Cold SG Compartment 448 12-RC-1221-BB1 12-RC-1221-BB1-13 Sl-ACC-CL2 7N 10.126 -216.79 249.88 546.57 Cold SG Compartment 449 12-RC-1221-BB1 12-RC-1221-BB1-14 SI-ACC-CL2 7N 10.126 -215.13 196.36 533.24 Cold SG Compartment Page 155 of 260 South Texas Project Risk-Informed GSI-191 Evaluation Volume 3: CASA Grande Analysis RI-GSI191-V03 Revision 1 No. Line Number Location Name System Category Pipe ID X Y Z Side Compartment 450 12-RC-1312-BB1 12-RC-1312-BB1-1 RH 7E 10.126 84.95 238 500.48 Hot SG Compartment 451 12-RC-1312-B81 12-RC-1312-BB1-2 RH 7A 10.126 76.9 241.25 491.8 Hot SG Compartment 452 12-RC-1312-B81 12-RC-1312-BB1-3 RH 7A 10.126 73.64 242.57 483.31 Hot SG Compartment 453 12-RC-1312-BB1 12-RC-1312-BB1-4 RH 7A 10.126 73.64 242.57 468 Hot SG Compartment 454 12-RC-1312-BB1 12-RC-1312-BB1-5 RH 7A 10.126 65.16 251.06 456 Hot SG Compartment 455 12-RC-1312-BB1 12-RC-1312-BB1-6 RH 7A 10.126 45.51 270.7 456 Hot SG Compartment 456 12-RC-1312-BB1 12-RC-1312-BB1-7 RH 7A 10.126 42 279.18 456 Hot SG Compartment 457 12-RC-1312-BB1 12-RC-1312-BB1-8 RH 7A 10.126 42 386.95 456 Hot SG Compartment 458 12-RC-1312-BB1 12-RC-1312-BB1-9 RH 7E 10.126 42 487.69 456 Hot SG Compartment 459 12-RC-1312-BB1 12-RC-1312-BB1-10 RH 7E 10.126 54 499.69 456 Hot SG Compartment 460 12-RC-1312-BB1 12-RC-1312-BB1-11 RH 7E 10.126 199.56 499.69 456 Hot SG Compartment 461 12-RC-1322-B81 12-RC-1322-BB1-1 Sl-ACC-CL3 7N 10.126 283.34 302.01 548.18 Cold SG Compartment 462 12-RC-1322-BB1 12-RC-1322-BB1-1A Sl-ACC-CL3 7N 10.126 260.67 279.34 548.18 Cold SG Compartment 463 12-RC-1322-BB1 12-RC-1322-B81-2 Sl-ACC-CL3 7N 10.126 242.84 261.51 548.18 Cold SG Compartment 464 12-RC-1322-BB1 12-RC-1322-BB1-3 Sl-ACC-CL3 7N 10.126 238 249.97 546.51 Cold SG Compartment 465 12-RC-1322-BB1 12-RC-1322-BB1-4 Sl-ACC-CL3 7N 10.126 238 196.66 533.24 Cold SG Compartment 466 12-RH-1101-BB1 12-RH-1101-BB1-1 RH 7E 10.126 -108.02 -501 455.7 Hot SG Compartment 467 12-RH-1101-BB1 12-RH-1101-BB1-2 RH 7E 10.126 -226.24 -501 455.83 Hot SG Compartment 468 12-RH-1101-BB1 12-RH-1101-BB1-3 RH 7E 10.126 -237.38 -496.32 455.84 Hot SG Compartment 469 12-RH-1101-BB1 12-RH-1101-BB1-3A RH 7E 10.126 -328.79 -404.91 455.94 Hot SG Compartment 470 12-RH-1101-BB1 12-RH-1101-BB1-4 RH 7E 10.126 -372.86 -360.84 455.99 Hot SG Compartment 471 12-RH-1101-BB1 12-RH-1101-B11-5 RH 7E 10.126 -408.95 -324.75 456.03 Hot SG Compartment 472 12-RH-1101-8B1 12-RH-1101-BB1-6 RH 7E 10.126 -413.64 -313.53 456.04 Hot SG Compartment 473 12-RH-1101-BB1 12-RH-1101-BB1-7 RH 7E 10.126 -413.64 -255.38 456.04 Hot SG Compartment 474 12-RH-1101-BB1 12-RH-1101-BB1-8 RH 7E 10.126 -429.64 -239.38 456.05 Hot SG Compartment 475 12-RH-1101-BB1 12-RH-1101-BB1-9 RH 7E 10.126 -479.81 -239.37 456.11 Hot SG Compartment 476 12-RH-1101-BB1 12-RH-1101-BB1-10 RH 7E 10.126 -571.54 -239.38 456.21 Hot RHR Compartment 477 12-RH-1101-BB1 12-RH-1101-BB1-11 RH 7E 10.126 -587.53 -239.38 440.23 Hot RHR Compartment 478 12-RH-1101-BB1 12-RH-1101-BB1-12 RH 7E 10.126 -587.61 -239.38 369.23 Hot RHR Compartment 479 12-RH-1101-BB1 12-RH-1101-BB1-13 RH 7E 10.126 -587.77 -239.38 225.23 Hot RHR Compartment 480 12-RH-1101-BB1 12-RH-1101-BB1-14 RH 7E 10.126 -587.85 -239.38 149.71 Hot RHR Compartment 481 12-RH-1101-BB1 12-RH-1101-BB1-15 RH 7E 10.126 -587.87 -223.38 129.04 Hot RHR Compartment 482 12-RH-1101-BB1 12-RH-1101-8B1-16 RH 7E 10.126 -587.87 -190.38 129.04 Hot RHR Compartment 483 12-RH-1201-BB1 12-RH-1201-BB1-1 RH 7E 10.126 -18.01 453.99 456.01 Hot SG Compartment 484 12-RH-1201-BB1 12-RH-1201-1B1-2 RH 7E 10.126 -18.01 485.99 456.01 Hot SG Compartment 485 12-RH-1201-BB1 12-RH-1201-BB1-3 RH 7E 10.126 -34.01 501.99 456.01 Hot SG Compartment 486 12-RH-1201-8B1 12-RH-1201-B81-4 RH 7E 10.126 -226.44 501.99 456.01 Hot SG Compartment 487 12-RH-1201-BB1 12-RH-1201-B11-5 RH 7E 10.126 -237.76 497.31 456.01 Hot SG Compartment 488 12-RH-1201-8B1 12-RH-1201-BB1-6 RH 7E 10.126 -323.53 411.53 456.01 Hot SG Compartment 489 12-RH-1201-BB1 12-RH-1201-B81-7 RH 7E 10.126 -409.38 325.69 456.01 Hot SG Compartment 490 12-RH-1201-BB1 12-RH-1201-BB1-8 RH 7E 10.126 -414 314.43 456.01 Hot SG Compartment Page 156 of 260 South Texas Project Risk-Informed GSI-191 Evaluation Volume 3: CASA Grande Analysis RI-GSI191-V03 Revision 1 No. Line Number Location Name System Category Pipe ID X Y z Side Compartment 491 12-RH-1201-BB1 12-RH-1201-BB1-9 RH 7E 10.126 -414 256.38 456.01 Hot SG Compartment 492 12-RH-1201-BB1 12-RH-1201-BB1-10 RH 7E 10.126 -430 240.38 456.01 Hot SG Compartment 493 12-RH-1201-BB1 12-RH-1201-BB1-11 RH 7E 10.126 -530.54 240.38 456.01 Hot RHR Compartment 494 12-RH-1201-BB1 12-RH-1201-BB1-12 RH 7E 10.126 -588 240.38 432.01 Hot RHR Compartment 495 12-RH-1201-BB1 12-RH-1201-BB1-13 RH 7E 10.126 -588 240.38 423.01 Hot RHR Compartment 496 12-RH-1201-BB1 12-RH-1201-BB1-14 RH 7E 10.126 -588 240.38 237.01 Hot RHR Compartment 497 12-RH-1201-BB1 12-RH-1201-BBl-15 RH 7E 10.126 -588 240.38 153.01 Hot RHR Compartment 498 12-RH-1201-BB1 12-RH-1201-BBl-16 RH 7E 10.126 -588 213.12 129.01 Hot RHR Compartment 499 12-RH-1201-BB1 12-RH-1201-BB1-17 RH 7E 10.126 -588 191.38 129.01 Hot RHR Compartment 500 12-RH-1301-BB1 12-RH-1301-BB1-1 RH 7E 10.126 232.84 499.69 456 Hot SG Compartment 501 12-RH-1301-BB1 12-RH-1301-BB1-2 RH 7E 10.126 251.71 499.69 456 Hot SG Compartment 502 12-RH-1301-BB1 12-RH-1301-BB1-3 RH 7E 10.126 263.02 495 456 Hot SG Compartment 503 12-RH-1301-BB1 12-RH-1301-BB1-4 RH 7E 10.126 441.96 316.06 456 Hot SG Compartment 504 12-RH-1301-BB1 12-RH-1301-BB1-5 RH 7E 10.126 454.32 311.37 456 Hot SG Compartment 505 12-RH-1301-BB1 12-RH-1301-BB1-5A RH 7E 10.126 515.15 311.37 456 Hot RHR Compartment 506 12-RH-1301-BB1 12-RH-1301-BB1-6 RH 7E 10.126 523.96 311.37 456 Hot RHR Compartment 507 12-RH-1301-BB1 12-RH-1301-BB1-7 RH 7E 10.126 539.96 311.37 435 Hot RHR Compartment 508 12-RH-1301-BB1 12-RH-1301-BB1-8 RH 7E 10.126 539.96 311.37 415 Hot RHR Compartment 509 12-RH-1301-BB1 12-RH-1301-BB1-9 RH 7E 10.126 539.96 295.37 399 Hot RHR Compartment 510 12-RH-1301-BB1 12-RH-1301-BB1-10 RH 7E 10.126 539.96 265.37 399 Hot RHR Compartment 511 12-S1-1125-BB1 12-SI-1125-BB1-1 SI-ACC-CL1 70 10.126 -383.87 -361.72 273.02 Cold Below SG Compartment 512 12-S1-1125-BB1 12-S1-1125-B81-2 Sl-ACC-CL1 70 10.126 -364.07 -381.51 273.02 Cold Below SG Compartment 513 12-S1-1125-BB1 12-SI-1125-BB1-3 Sl-ACC-CL1 70 10.126 -355.59 -390 273.02 Cold Below SG Compartment 514 12-S1-1125-BB1 12-SI-1125-BB1-4 S1-ACC-CL1 70 10.126 -344.27 -401.31 273.02 Cold Below SG Compartment 515 12-S1-1218-BB1 12-SI-1218-BB1-1 Sl-ACC-CL2 70 10.126 -383.87 361.49 273.01 Cold Below SG Compartment 516 12-S1-1218-BB1 12-Sl-1218-BB1-2 Sl-ACC-CL2 70 10.126 -365.49 379.87 273.01 Cold Below SG Compartment 517 12-S1-1218-BB1 12-51-1218-BB1-3 SI-ACC-CL2 70 10.126 -354.17 391.18 273.01 Cold Below SG Compartment 518 12-SI-1218-BB1 12-S1-1218-BB1-4 Sl-ACC-CL2 70 10.126 -344.27 401.08 273.01 Cold Below SG Compartment 519 12-SI-1315-BB1 12-S1-1315-BB1-1 SI-ACC-CL4 70 10.126 366.48 385.2 191.01 Cold Below SG Compartment 520 12-S1-1315-BB1 12-Sl-1315-BB1-2 Sl-ACC-CL4 70 10.126 340.31 359.04 191.01 Cold Below SG Compartment 521 12-SI-1315-BB1 12-SI-131S-BB1-3 Sl-ACC-CL4 70 10.126 329 347.73 207.01 Cold Below SG Compartment 522 12-Sl-1315-BB1 12-SI-1315-BB1-4 Sl-ACC-CL4 70 10.126 329 347.73 225.01 Cold Below SG Compartment 523 12-SI-1315-BB1 12-SI-1315-BB1-5 Sl-ACC-CL1 70 10.126 329 347.73 237.01 Cold Below SG Compartment 524 12-SI-1315-BB1 12-SI-1315-BB1-6 Sl-ACC-CL4 70 10.126 329 347.73 379.07 Cold SG Compartment 525 12-S1-1315-B81 12-S1-1315-BB1-7 SI-ACC-CL4 70 10.126 329 347.73 447.73 Cold SG Compartment 526 12-SI-1315-BB1 12-SI-1315-BB1-8 Sl-ACC-CL4 7D 10.126 329 347.73 532.19 Cold SG Compartment 527 12-SI-1315-BB1 12-SI-1315-BB1-9 Sl-ACC-CL4 7D 10.126 317.69 336.41 548.19 Cold SG Compartment 528 12-Sl-1315-BB1 12-S1-1315-BB1-10 Sl-ACC-CL4 7D 10.126 309.42 328.15 548.19 Cold SG Compartment 529 16-RC-1412-NSS 16-RC-1412-NSS-1 Pressurizer Surge Line 4B 12.814 12 -678 688.5 Hot Surge Line 530 16-RC-1412-NSS 16-RC-1412-NSS-3 Pressurizer Surge Line 4B 12.814 181.01 -678 528.97 Hot Surge Line 531 16-RC-1412-NSS 16-RC-1412-NSS-4 Pressurizer Surge Line 4B 12.814 205 -654 528.41 Hot Surge Line Page 157 of 260 South Texas Project Risk-Informed GSI-191 Evaluation Volume 3: CASA Grande Analysis RI-GSI191-V03 Revision 1 No. Line Number Location Name System Category Pipe ID X Y Z Side Compartment 532 16-RC-1412-NS5 16-RC-1412-NSS-5 Pressurizer Surge Line 4B 12.814 205 -531 526.97 Hot SG Compartment 533 16-RC-1412-NSS 16-RC-1412-NSS-6 Pressurizer Surge Line 4B 12.814 180.85 -507 526.41 Hot SG Compartment 534 16-RC-1412-NS5 16-RC-1412-N55-7 Pressurizer Surge Line 4B 12.814 91.98 -507 525.37 Hot SG Compartment 535 16-RC-1412-NSS 16-RC-1412-NSS-8 Pressurizer Surge Line 4B 12.814 12 -400.56 523.22 Hot SG Compartment 536 16-RC-1412-NSS 16-RC-1412-NSS-9 Pressurizer Surge Line 4C 12.814 89.65 -262.75 522 Hot SG Compartment 537 16-RC-1412-NSS 16-RC-1412-NSS-PRZ-1-N1-SE Pressurizer Surge Line 4A 12.814 12 -678 691 Hot Surge Line 538 27.5-RC-1103-NSS
-LOOP 1 27.5-RC-1103-NSS-1 RC Cold Leg 1 3C 27.5 -264.83 -202.37 522 Cold SG Compartment 539 27.5-RC-1103-NSS
-LOOP 1 27.5-RC-1103-NSS-3 RC 71 3.438 -252.54 -190.08 541.08 Cold SG Compartment 540 27.5-RC-1103-NSS
-LOOP 1 27.5-RC-1103-NSS-4 Sl-ACC-CL1 7N 10.126 -212.31 -149.85 522 Cold SG Compartment 541 27.5-RC-1103-NSS
-LOOP 1 27.5-RC-1103-NSS-5 CV 8E 3.438 -201.49 -112.07 522 Cold SG Compartment 542 27.5-RC-1103-NSS
-LOOP 1 27.5-RC-1103-NSS-6 RC Cold Leg 1 3C 27.5 -122.74 -60.28 522 Cold RX Cavity 543 27.5-RC-1103-NSS
-LOOP 1 27.5-RC-1103-NSS-7 RC Cold Leg 1 3C 27.5 -117.38 -54.92 522 Cold RX Cavity 544 27.5-RC-1103-NSS
-LOOP 1 27.5-RC-1103-NSS-RPV1-N2ASE RC Cold Leg 1 3A 27.5 -108.79 -51.27 522 Cold RX Cavity 545 27.5-RC-1203-NSS
-LOOP 2 27.5-RC-1203-NSS-1 RC Cold Leg 2 3C 27.5 -264.83 202.37 522 Cold SG Compartment 546 27.5-RC-1203-NSS
-LOOP 2 27.5-RC-1203-NSS-3 Sl-ACC-CL2 7N 10.126 -214.54 177.45 528.52 Cold SG Compartment 547 27.5-RC-1203-NSS
-LOOP 2 27.5-RC-1203-NSS-4 RC Cold Leg 2 3C 27.5 -122.74 60.28 522 Cold RX Cavity 548 27.5-RC-1203-NSS
-LOOP 2 27.5-RC-1203-NSS-5 RC Cold Leg 2 3C 27.5 -110.41 51.96 522 Cold RX Cavity 549 27.5-RC-1203-NSS
-LOOP 2 27.5-RC-1203-NSS-RPV1-N2BSE RC Cold Leg 2 3A 27.5 -108.79 51.27 522 Cold RX Cavity 550 27.5-RC-1303-NSS
-LOOP 3 27.5-RC-1303-NSS-1 RC Cold Leg 3 3C 27.5 288.83 202.37 522 Cold SG Compartment 551 27.5-RC-1303-NSS
-LOOP 3 27.5-RC-1303-NSS-3 Sl-ACC-CL3 7N 10.126 238 177.01 528.34 Cold SG Compartment 552 27.5-RC-1303-NSS
-LOOP 3 27.5-RC-1303-NSS-4 Cv 8E 3.438 198.5 139 522 Cold SG Compartment 553 27.5-RC-1303-NSS
-LOOP 3 27.5-RC-1303-NSS-5 RC Cold Leg 3 3C 27.5 146.74 60.28 522 Cold RX Cavity 554 27.5-RC-1303-NSS
-LOOP 3 27.5-RC-1303-NSS-6 RC Cold Leg 3 3C 27.5 134.41 51.96 522 Cold RX Cavity 555 27.5-RC-1303-NSS
-LOOP 3 27.5-RC-1303-NSS-RPV1-N2CSE RC Cold Leg 3 3A 27.5 132.79 51.27 522 Cold RX Cavity 556 27.5-RC-1403-NSS
-LOOP 4 27.5-RC-1403-NSS-1 RC Cold Leg 4 3C 27.5 288.83 -202.37 522 Cold SG Compartment 557 27.5-RC-1403-NSS
-LOOP 4 27.5-RC-1403-NSS-3 RC 71 3.438 273.56 -187.1 541.06 Cold SG Compartment 558 27.5-RC-1403-NSS
-LOOP 4 27.5-RC-1403-NSS-4 RC 71 3.438 254.15 -186.75 535.48 Cold SG Compartment 559 27.5-RC-1403-NSS
-LOOP 4 27.5-RC-1403-NSS-5 RC Cold Leg 4 3C 27.5 146.74 -60.28 522 Cold RX Cavity 560 27.5-RC-1403-NSS
-LOOP 4 27.5-RC-1403-NSS-6 RC Cold Leg 4 3C 27.5 134.41 -51.96 522 Cold RX Cavity 561 27.5-RC-1403-NSS
-LOOP 4 27.5-RC-1403-NSS-RPV1-N2DSE RC Cold Leg 4 3A 27.5 132.79 -51.27 522 Cold RX Cavity 562 29-RC-1101-NSS
-LOOP 1 29-RC-1101-NSS-1 RC-Hot Leg 1 18 29 -36.35 -119.66 522 Hot RX Cavity 563 29-RC-1101-NSS
-LOOP 1 29-RC-1101-NSS-2 SI 7G 6.813 -99.42 -222.46 522 Hot SG Compartment 564 29-RC-1101-NSS
-LOOP 1 29-RC-1101-NSS-3 RHR-Suction 7E 10.126 -67.51 -235.35 507.55 Hot SG Compartment 565 29-RC-1101-NSS
-LOOP 1 29-RC-1101-NSS-4 RC-Hot Leg 1 1B 29 -101.37 -280.59 522 Hot SG Compartment 566 29-RC-1101-N5S
-LOOP 1 29-RC-1101-NSS-5.1 RC-Hot Leg 1 1B 29 -115.72 -316.11 539.86 Hot SG Compartment 567 29-RC-1101-NSS
-LOOP 1 29-RC-1101-NSS-RPV1-NIASE RC-Hot Leg 1 1A 29 -34.1 -114.1 522 Hot RX Cavity 568 29-RC-1101-NSS
-LOOP 1 29-RC-1101-NSS-RSG-1A-IN-SE RC-Hot Leg 1 2 29 -115.85 -316.43 540.28 Hot SG Compartment 569 29-RC-1201-NSS
-LOOP 2 29-RC-1201-NSS-1 RC-Hot Leg 2 1B 29 -36.35 119.66 522 Hot RX Cavity 570 29-RC-1201-NSS
-LOOP 2 29-RC-1201-NSS-2 SI 7G 6.813 -99.84 222.29 522 Hot SG Compartment 571 29-RC-1201-NSS
-LOOP 2 29-RC-1201-NSS-3 RC 7E 10.126 -67.5 235.33 507.55 Hot SG Compartment 572 29-RC-1201-NSS
-LOOP 2 29-RC-1201-NSS-4 RC-Hot Leg 2 1B 29 -101.37 280.59 522 Hot SG Compartment Page 158 of 260 South Texas Project Risk-Informed GSI-191 Evaluation Volume 3: CASA Grande Analysis RI-GSI191-V03 Revision 1 No. Line Number Location Name System Category Pipe ID X Y Z Side Compartment 573 29-RC-1201-NSS
-LOOP 2 29-RC-1201-NSS-5.1 RC-Hot Leg 2 lB 29 -115.72 316.11 539.86 Hot SG Compartment 574 29-RC-1201-NSS
-LOOP 2 29-RC-1201-RPV1-N1BSE RC-Hot Leg 2 1A 29 -34.1 114.1 522 Hot RX Cavity 575 29-RC-1201-NSS
-LOOP 2 29-RC-1201-RSG-1B-IN-SE RC-Hot Leg 2 2 29 -115.85 316.43 540.28 Hot SG Compartment 576 29-RC-1301-NSS
-LOOP 3 29-RC-1301-NSS-1 RC-Hot Leg 3 1B 29 60.35 119.67 522 Hot RX Cavity 577 29-RC-1301-NSS
-LOOP 3 29-RC-1301-NSS-2 SI 7G 6.813 123.84 222.29 522 Hot SG Compartment 578 29-RC-1301-NSS
-LOOP 3 29-RC-1301-NSS-3 RC 7E 10.126 91.51 235.35 507.55 Hot SG Compartment 579 29-RC-1301-NSS
-LOOP 3 29-RC-1301-NSS-4 RC-Hot Leg 3 1B 29 125.37 280.6 522 Hot SG Compartment 580 29-RC-1301-NSS
-LOOP 3 29-RC-1301-NSS-5.1 RC-Hot Leg 3 1B 29 139.72 316.12 539.86 Hot SG Compartment 581 29-RC-1301-NSS
-LOOP 3 29-RC-1301-RPV1-N1CSE RC-Hot Leg 3 1A 29 58.1 114.11 522 Hot RX Cavity 582 29-RC-1301-NSS
-LOOP 3 29-RC-1301-RSG-1C-IN-5E RC-Hot Leg 3 2 29 139.85 316.44 540.28 Hot SG Compartment 583 29-RC-1401-NSS
-LOOP 4 29-RC-1401-NSS-1 RC-Hot Leg 4 1B 29 60.35 -119.66 522 Hot RX Cavity 584 29-RC-1401-NSS
-LOOP 4 29-RC-1401-NSS-2 Pressurizer Surge Line 4C 12.814 95.22 -260.5 522 Hot SG Compartment 585 29-RC-1401-NSS
-LOOP 4 29-RC-1401-NSS-3 RC-Hot Leg 4 iC 29 125.37 -280.59 522 Hot SG Compartment 586 29-RC-1401-NSS
-LOOP 4 29-RC-1401-NSS-4.1 RC-Hot Leg 4 1B 29 139.72 -316.11 539.86 Hot SG Compartment 587 29-RC-1401-NSS
-LOOP 4 29-RC-1401-NSS-RPV1-N1DSE RC-Hot Leg 4 1A 29 58.1 -114.1 522 Hot RX Cavity 588 29-RC-1401-NSS
-LOOP 4 29-RC-1401-NSS-RSG-1D-IN-SE RC-Hot Leg 4 2 29 139.85 -316.43 540.28 Hot SG Compartment 589 31-RC-1102-NSS
-LOOP 1 31-RC-1102-NSS-1.1 RC Cold Leg 1 3D 31 -195.08 -364.07 538.7 Cold SG Compartment 590 31-RC-1102-NSS
-LOOP 1 31-RC-1102-NSS-2 RC Cold Leg 1 3D 31 -206.74 -363.05 506.56 Cold SG Compartment 591 31-RC-1102-NSS
-LOOP 1 31-RC-1102-NSS-3 RC Cold Leg 1 3D 31 -206.74 -363.05 441.31 Cold SG Compartment 592 31-RC-1102-NSS
-LOOP 1 31-RC-1102-NSS-4 RC Cold Leg 1 3D 31 -234.4 -338.57 404.31 Cold SG Compartment 593 31-RC-1102-NSS
-LOOP 1 31-RC-1102-NSS-5 RC 7K* 1.689 -252 -323 425.33 Cold SG Compartment 594 31-RC-1102-NSS
-LOOP 1 31-RC-1102-NSS-6 RC 7K 1.689 -271.12 -306.08 383.29 Cold SG Compartment 595 31-RC-1102-NSS
-LOOP 1 31-RC-1102-NSS-7 RC 7J 2.626 -278.44 -299.61 425.33 Cold SG Compartment 596 31-RC-1102-NSS
-LOOP 1 31-RC-1102-NSS-8 RC Cold Leg 1 3D 31 -289.67 -289.67 404.31 Cold SG Compartment 597 31-RC-1102-NSS
-LOOP 1 31-RC-1102-NSS-9 RC Cold Leg 1 3D 31 -322.81 -260.35 448.56 Cold SG Compartment 598 31-RC-1102-NSS
-LOOP 1 31-RC-1102-NSS-RSG-1A-ON-SE RC Cold Leg 1 3B 31 -195.04 -364.07 538.75 Cold SG Compartment 599 31-RC-1202-NSS
-LOOP 2 31-RC-1202-NSS-1.1 RC Cold Leg 2 3D 31 -195.08 364.07 538.7 Cold SG Compartment 600 31-RC-1202-NSS
-LOOP 2 31-RC-1202-NSS-2 RC Cold Leg 2 3D 31 -206.74 363.05 506.56 Cold SG Compartment 601 31-RC-1202-NSS
-LOOP 2 31-RC-1202-NSS-3 RC Cold Leg 2 3D 31 -206.74 363.05 441.31 Cold SG Compartment 602 31-RC-1202-NSS
-LOOP 2 31-RC-1202-NSS-4 RC Cold Leg 2 3D 31 -234.43 338.54 404.31 Cold SG Compartment 603 31-RC-1202-NSS
-LOOP 2 31-RC-1202-NSS-5 RC 7K 1.689 -249.25 325.43 425.33 Cold SG Compartment 604 31-RC-1202-NSS
-LOOP 2 31-RC-1202-NSS-6 RC 7J 2.626 -278.44 299.61 425.33 Cold SG Compartment 605 31-RC-1202-NSS
-LOOP 2 31-RC-1202-NSS-7 RC 7K 1.689 -271.15 306.06 383.29 Cold SG Compartment 606 31-RC-1202-NSS
-LOOP 2 31-RC-1202-NSS-8 RC Cold Leg 2 3D 31 -289.7 289.65 404.31 Cold SG Compartment 607 31-RC-1202-NSS
-LOOP 2 31-RC-1202-NSS-9 RC Cold Leg 2 3D 31 -322.81 260.35 448.56 Cold SG Compartment 608 31-RC-1202-NSS
-LOOP 2 31-RC-1202-NSS-RSG-1B-ON-SE RC Cold Leg 2 3B 31 -195.05 364.07 538.74 Cold SG Compartment 609 31-RC-1302-NSS
-LOOP 3 31-RC-1302-NSS-1.1 RC Cold Leg 3 3D 31 219.08 364.07 538.7 Cold SG Compartment 610 31-RC-1302-NSS
-LOOP 3 31-RC-1302-NSS-2 RC Cold Leg 3 3D 31 230.74 363.05 506.56 Cold SG Compartment 611 31-RC-1302-NSS
-LOOP 3 31-RC-1302-NSS-3 RC Cold Leg 3 3D 31 230.74 363.05 441.29 Cold SG Compartment 612 31-RC-1302-NSS
-LOOP 3 31-RC-1302-NSS-4 RC Cold Leg 3 3D 31 258.45 338.53 404.31 Cold SG Compartment 613 31-RC-1302-NSS
-LOOP 3 31-RC-1302-NSS-5 RC 7K 1.689 272.81 325.82 425.33 Cold SG Compartment Page 159 of 260 South Texas Project Risk-Informed GSI-191 Evaluation Volume 3: CASA Grande Analysis RI-GSI191-V03 Revision 1 No. Line Number Location Name System Category Pipe ID X Y Z Side Compartment 614 31-RC-1302-N5S
-LOOP 3 31-RC-1302-NSS-6 RC 7J 2.626 302.44 299.61 425.33 Cold SG Compartment 615 31-RC-1302-NSS
-LOOP 3 31-RC-1302-NSS-7 RC 71 3.438 295.13 306.07 383.29 Cold SG Compartment 616 31-RC-1302-NSS
-LOOP 3 31-RC-1302-NSS-8 RC Cold Leg 3 3D 31 313.67 289.67 404.31 Cold SG Compartment 617 31-RC-1302-NSS
-LOOP 3 31-RC-1302-NSS-9 RC Cold Leg 3 3D 31 346.81 260.35 448.56 Cold SG Compartment 618 31-RC-1302-NSS
-LOOP 3 31-RC-1302-NSS-RSG-1C-ON-SE RC Cold Leg 3 3B 31 219.08 364.07 538.7 Cold SG Compartment 619 31-RC-1402-NSS
-LOOP 4 31-RC-1402-NSS-1.1 RC Cold Leg 4 3D 31 219.08 -364.07 538.7 Cold SG Compartment 620 31-RC-1402-NSS
-LOOP 4 31-RC-1402-NSS-2 RC Cold Leg 4 3D 31 230.74 -363.05 506.56 Cold SG Compartment 621 31-RC-1402-NSS
-LOOP 4 31-RC-1402-NSS-3 RC Cold Leg 4 3D 31 230.74 -363.05 441.31 Cold SG Compartment 622 31-RC-1402-NSS
-LOOP 4 31-RC-1402-NSS-4 RC Cold Leg 4 3D 31 258.45 -338.53 404.31 Cold SG Compartment 623 31-RC-1402-NSS
-LOOP 4 31-RC-1402-NSS-5 RC 7K 1.689 273.37 -325.32 425.33 Cold SG Compartment 624 31-RC-1402-NS5
-LOOP 4 31-RC-1402-NSS-6 RC 7J 2.626 302.44 -299.61 425.33 Cold SG Compartment 625 31-RC-1402-NSS
-LOOP 4 31-RC-1402-NSS-7 RC 7K 1.689 295.15 -306.06 383.29 Cold SG Compartment 626 31-RC-1402-NSS
-LOOP 4 31-RC-1402-NSS-8 RC Cold Leg 4 3D 31 313.67 -289.67 404.31 Cold SG Compartment 627 31-RC-1402-NSS
-LOOP 4 31-RC-1402-NSS-9 RC Cold Leg 4 3D 31 346.81 -260.35 448.56 Cold SG Compartment 628 31-RC-1402-NSS
-LOOP 4 31-RC-1402-NSS-RSG-1D-ON-SE RC Cold Leg 4 3B 31 219.05 -364.07 538.74 Cold SG Compartment Page 160 of 260